21651572293 has 16 divisors (see below), whose sum is σ = 23407727616. Its totient is φ = 19908483840.

The previous prime is 21651572287. The next prime is 21651572321. The reversal of 21651572293 is 39227515612.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 21651572293 - 2¹³ = 21651564101 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21651572213) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7985208 + ... + 7987918.

It is an arithmetic number, because the mean of its divisors is an integer number (1462982976).

Almost surely, 2^21651572293 is an apocalyptic number.

It is an amenable number.

21651572293 is a deficient number, since it is larger than the sum of its proper divisors (1756155323).

21651572293 is a wasteful number, since it uses less digits than its factorization.

21651572293 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4884.

The product of its digits is 226800, while the sum is 43.

The spelling of 21651572293 in words is "twenty-one billion, six hundred fifty-one million, five hundred seventy-two thousand, two hundred ninety-three".