21751750773 has 20 divisors (see below), whose sum is σ = 32613290688. Its totient is φ = 14447642760.

The previous prime is 21751750771. The next prime is 21751750781. The reversal of 21751750773 is 37705715712.

21751750773 is a `hidden beast` number, since 2 + 1 + 75 + 1 + 7 + 507 + 73 = 666.

It is not a de Polignac number, because 21751750773 - 2¹ = 21751750771 is a prime.

It is a hoax number, since the sum of its digits (45) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21751750771) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 473511 + ... + 517412.

Almost surely, 2^21751750773 is an apocalyptic number.

It is an amenable number.

21751750773 is a deficient number, since it is larger than the sum of its proper divisors (10861539915).

21751750773 is an equidigital number, since it uses as much as digits as its factorization.

21751750773 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 991206 (or 991197 counting only the distinct ones).

The product of its (nonzero) digits is 360150, while the sum is 45.

The spelling of 21751750773 in words is "twenty-one billion, seven hundred fifty-one million, seven hundred fifty thousand, seven hundred seventy-three".