21661465732412 has 12 divisors (see below), whose sum is σ = 41353707307416. Its totient is φ = 9846120787440.

The previous prime is 21661465732391. The next prime is 21661465732429. The reversal of 21661465732412 is 21423756416612.

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, 246153019643 + ... + 246153019730.

It is an arithmetic number, because the mean of its divisors is an integer number (3446142275618).

Almost surely, 2^{21661465732412} is an apocalyptic number.

21661465732412 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

21661465732412 is a deficient number, since it is larger than the sum of its proper divisors (19692241575004).

21661465732412 is a wasteful number, since it uses less digits than its factorization.

21661465732412 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 492306039388 (or 492306039386 counting only the distinct ones).

The product of its digits is 2903040, while the sum is 50.

The spelling of 21661465732412 in words is "twenty-one trillion, six hundred sixty-one billion, four hundred sixty-five million, seven hundred thirty-two thousand, four hundred twelve".