21035705757 has 16 divisors (see below), whose sum is σ = 30617448960. Its totient is φ = 12740554800.

The previous prime is 21035705753. The next prime is 21035705783. The reversal of 21035705757 is 75750753012.

It is a happy number.

It is not a de Polignac number, because 21035705757 - 2² = 21035705753 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21035705753) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 157657 + ... + 258702.

It is an arithmetic number, because the mean of its divisors is an integer number (1913590560).

Almost surely, 2^21035705757 is an apocalyptic number.

It is an amenable number.

21035705757 is a deficient number, since it is larger than the sum of its proper divisors (9581743203).

21035705757 is a wasteful number, since it uses less digits than its factorization.

21035705757 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 417904.

The product of its (nonzero) digits is 257250, while the sum is 42.

The spelling of 21035705757 in words is "twenty-one billion, thirty-five million, seven hundred five thousand, seven hundred fifty-seven".