27780021504 has 432 divisors, whose sum is σ = 90240106320. Its totient is φ = 8174960640.

The previous prime is 27780021457. The next prime is 27780021551. The reversal of 27780021504 is 40512008772.

27780021504 is a `hidden beast` number, since 2 + 77 + 80 + 0 + 2 + 1 + 504 = 666.

It is an interprime number because it is at equal distance from previous prime (27780021457) and next prime (27780021551).

It can be written as a sum of positive squares in 8 ways, for example, as 7456667904 + 20323353600 = 86352^2 + 142560^2 .

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 42026934 + ... + 42027594.

It is an arithmetic number, because the mean of its divisors is an integer number (208889135).

Almost surely, 2^27780021504 is an apocalyptic number.

27780021504 is a gapful number since it is divisible by the number (24) 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 27780021504, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (45120053160).

27780021504 is an abundant number, since it is smaller than the sum of its proper divisors (62460084816).

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

27780021504 is a wasteful number, since it uses less digits than its factorization.

27780021504 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 766 (or 749 counting only the distinct ones).

The product of its (nonzero) digits is 31360, while the sum is 36.

The spelling of 27780021504 in words is "twenty-seven billion, seven hundred eighty million, twenty-one thousand, five hundred four".