28405731600 has 225 divisors, whose sum is σ = 100471466953. Its totient is φ = 7431939840.

The previous prime is 28405731509. The next prime is 28405731611. The reversal of 28405731600 is 613750482.

The square root of 28405731600 is 168540.

It is a perfect power (a square), and thus also a powerful number.

28405731600 is a `hidden beast` number, since 2 + 8 + 40 + 5 + 7 + 3 + 1 + 600 = 666.

It can be written as a sum of positive squares in 7 ways, for example, as 5819248656 + 22586482944 = 76284^2 + 150288^2 .

It is a tau number, because it is divible by the number of its divisors (225).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 44 ways as a sum of consecutive naturals, for example, 535957174 + ... + 535957226.

Almost surely, 2^28405731600 is an apocalyptic number.

28405731600 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

28405731600 is the 168540-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28405731600

28405731600 is an abundant number, since it is smaller than the sum of its proper divisors (72065735353).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

28405731600 is an frugal number, since it uses more digits than its factorization.

28405731600 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 236 (or 63 counting only the distinct ones).

The product of its (nonzero) digits is 40320, while the sum is 36.

Multiplying 28405731600 by its sum of digits (36), we get a square (1022606337600 = 1011240²).

28405731600 divided by its sum of digits (36) gives a square (789048100 = 28090²).

The spelling of 28405731600 in words is "twenty-eight billion, four hundred five million, seven hundred thirty-one thousand, six hundred".