21772532857 has 2 divisors, whose sum is σ = 21772532858. Its totient is φ = 21772532856.

The previous prime is 21772532807. The next prime is 21772532911. The reversal of 21772532857 is 75823527712.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16340253241 + 5432279616 = 127829^2 + 73704^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21772532857 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21772532857.

It is not a weakly prime, because it can be changed into another prime (21772532807) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10886266428 + 10886266429.

It is an arithmetic number, because the mean of its divisors is an integer number (10886266429).

Almost surely, 2^21772532857 is an apocalyptic number.

It is an amenable number.

21772532857 is a deficient number, since it is larger than the sum of its proper divisors (1).

21772532857 is an equidigital number, since it uses as much as digits as its factorization.

21772532857 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1646400, while the sum is 49.

The spelling of 21772532857 in words is "twenty-one billion, seven hundred seventy-two million, five hundred thirty-two thousand, eight hundred fifty-seven".