21057722999 has 2 divisors, whose sum is σ = 21057723000. Its totient is φ = 21057722998.

The previous prime is 21057722951. The next prime is 21057723031. The reversal of 21057722999 is 99922775012.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21057722999 is a prime.

It is a super-2 number, since 2×21057722999² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21057722999.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21057722929) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10528861499 + 10528861500.

It is an arithmetic number, because the mean of its divisors is an integer number (10528861500).

Almost surely, 2^21057722999 is an apocalyptic number.

21057722999 is a deficient number, since it is larger than the sum of its proper divisors (1).

21057722999 is an equidigital number, since it uses as much as digits as its factorization.

21057722999 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1428840, while the sum is 53.

The spelling of 21057722999 in words is "twenty-one billion, fifty-seven million, seven hundred twenty-two thousand, nine hundred ninety-nine".