21777638328 has 48 divisors (see below), whose sum is σ = 59064431400. Its totient is φ = 7248957120.

The previous prime is 21777638327. The next prime is 21777638339. The reversal of 21777638328 is 82383677712.

It is a happy number.

21777638328 is a `hidden beast` number, since 2 + 177 + 76 + 383 + 28 = 666.

It is a super-2 number, since 2×21777638328² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21777638327) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 162258 + ... + 264353.

Almost surely, 2^21777638328 is an apocalyptic number.

It is an amenable number.

21777638328 is an abundant number, since it is smaller than the sum of its proper divisors (37286793072).

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

21777638328 is a wasteful number, since it uses less digits than its factorization.

21777638328 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 427332 (or 427325 counting only the distinct ones).

The product of its digits is 4741632, while the sum is 54.

The spelling of 21777638328 in words is "twenty-one billion, seven hundred seventy-seven million, six hundred thirty-eight thousand, three hundred twenty-eight".