28709640540 has 192 divisors, whose sum is σ = 102825676800. Its totient is φ = 6514186752.

The previous prime is 28709640529. The next prime is 28709640563. The reversal of 28709640540 is 4504690782.

It is a happy number.

It is a super-2 number, since 2×28709640540² (a number of 22 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 490141 + ... + 545579.

It is an arithmetic number, because the mean of its divisors is an integer number (535550400).

Almost surely, 2^28709640540 is an apocalyptic number.

28709640540 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28709640540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (51412838400).

28709640540 is an abundant number, since it is smaller than the sum of its proper divisors (74116036260).

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

28709640540 is a wasteful number, since it uses less digits than its factorization.

28709640540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 55601 (or 55593 counting only the distinct ones).

The product of its (nonzero) digits is 483840, while the sum is 45.

The spelling of 28709640540 in words is "twenty-eight billion, seven hundred nine million, six hundred forty thousand, five hundred forty".