21165214445 has 32 divisors (see below), whose sum is σ = 27927244800. Its totient is φ = 15327157824.

The previous prime is 21165214423. The next prime is 21165214471. The reversal of 21165214445 is 54441256112.

It is a cyclic number.

It is not a de Polignac number, because 21165214445 - 2²⁸ = 20896778989 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2265554 + ... + 2274876.

It is an arithmetic number, because the mean of its divisors is an integer number (872726400).

Almost surely, 2^21165214445 is an apocalyptic number.

It is an amenable number.

21165214445 is a deficient number, since it is larger than the sum of its proper divisors (6762030355).

21165214445 is a wasteful number, since it uses less digits than its factorization.

21165214445 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10409.

The product of its digits is 38400, while the sum is 35.

The spelling of 21165214445 in words is "twenty-one billion, one hundred sixty-five million, two hundred fourteen thousand, four hundred forty-five".