21577393755 has 12 divisors (see below), whose sum is σ = 37400815920. Its totient is φ = 11507943312.

The previous prime is 21577393639. The next prime is 21577393771. The reversal of 21577393755 is 55739377512.

It is a happy number.

21577393755 is a `hidden beast` number, since 2 + 1 + 577 + 39 + 37 + 5 + 5 = 666.

It is not a de Polignac number, because 21577393755 - 2⁸ = 21577393499 is a prime.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 239748775 + ... + 239748864.

It is an arithmetic number, because the mean of its divisors is an integer number (3116734660).

Almost surely, 2^21577393755 is an apocalyptic number.

21577393755 is a deficient number, since it is larger than the sum of its proper divisors (15823422165).

21577393755 is a wasteful number, since it uses less digits than its factorization.

21577393755 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 479497650 (or 479497647 counting only the distinct ones).

The product of its digits is 6945750, while the sum is 54.

The spelling of 21577393755 in words is "twenty-one billion, five hundred seventy-seven million, three hundred ninety-three thousand, seven hundred fifty-five".