21225653690 has 16 divisors (see below), whose sum is σ = 38225344392. Its totient is φ = 8486001984.

The previous prime is 21225653689. The next prime is 21225653731. The reversal of 21225653690 is 9635652212.

It can be written as a sum of positive squares in 4 ways, for example, as 16654676809 + 4570976881 = 129053^2 + 67609^2 .

It is a super-2 number, since 2×21225653690² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 511469 + ... + 551408.

Almost surely, 2^21225653690 is an apocalyptic number.

21225653690 is a deficient number, since it is larger than the sum of its proper divisors (16999690702).

21225653690 is a wasteful number, since it uses less digits than its factorization.

21225653690 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1064881.

The product of its (nonzero) digits is 194400, while the sum is 41.

The spelling of 21225653690 in words is "twenty-one billion, two hundred twenty-five million, six hundred fifty-three thousand, six hundred ninety".