21661223112430 has 32 divisors (see below), whose sum is σ = 42886292397408. Its totient is φ = 7876808399680.

The previous prime is 21661223112421. The next prime is 21661223112523. The reversal of 21661223112430 is 3421132216612.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 813706567 + ... + 813733186.

It is an arithmetic number, because the mean of its divisors is an integer number (1340196637419).

Almost surely, 2^{21661223112430} is an apocalyptic number.

21661223112430 is a deficient number, since it is larger than the sum of its proper divisors (21225069284978).

21661223112430 is a wasteful number, since it uses less digits than its factorization.

21661223112430 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1627439793 (or 1627439771 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 34.

The spelling of 21661223112430 in words is "twenty-one trillion, six hundred sixty-one billion, two hundred twenty-three million, one hundred twelve thousand, four hundred thirty".