21294332057 has 4 divisors (see below), whose sum is σ = 21313194420. Its totient is φ = 21275469696.

The previous prime is 21294332027. The next prime is 21294332089. The reversal of 21294332057 is 75023349212.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 2909955136 + 18384376921 = 53944^2 + 135589^2 .

It is a cyclic number.

It is not a de Polignac number, because 21294332057 - 2²² = 21290137753 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21294332057.

It is not an unprimeable number, because it can be changed into a prime (21294332027) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9429488 + ... + 9431745.

It is an arithmetic number, because the mean of its divisors is an integer number (5328298605).

Almost surely, 2^21294332057 is an apocalyptic number.

It is an amenable number.

21294332057 is a deficient number, since it is larger than the sum of its proper divisors (18862363).

21294332057 is a wasteful number, since it uses less digits than its factorization.

21294332057 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18862362.

The product of its (nonzero) digits is 90720, while the sum is 38.

The spelling of 21294332057 in words is "twenty-one billion, two hundred ninety-four million, three hundred thirty-two thousand, fifty-seven".