21661020530612 has 12 divisors (see below), whose sum is σ = 37910785022880. Its totient is φ = 10829367666936.

The previous prime is 21661020530551. The next prime is 21661020530627. The reversal of 21661020530612 is 21603502016612.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 285606938 + ... + 285682769.

It is an arithmetic number, because the mean of its divisors is an integer number (3159232085240).

Almost surely, 2^{21661020530612} is an apocalyptic number.

It is an amenable number.

21661020530612 is a deficient number, since it is larger than the sum of its proper divisors (16249764492268).

21661020530612 is a wasteful number, since it uses less digits than its factorization.

21661020530612 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 571299190 (or 571299188 counting only the distinct ones).

The product of its (nonzero) digits is 25920, while the sum is 35.

The spelling of 21661020530612 in words is "twenty-one trillion, six hundred sixty-one billion, twenty million, five hundred thirty thousand, six hundred twelve".