21943659572836 has 9 divisors (see below), whose sum is σ = 38401420647891. Its totient is φ = 10971825102012.

The previous prime is 21943659572801. The next prime is 21943659572837. The reversal of 21943659572836 is 63827595634912.

It is a happy number.

The square root of 21943659572836 is 4684406.

It is a perfect power (a square), and thus also a powerful number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21943659572837) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 8197711 + ... + 10539913.

Almost surely, 2^{21943659572836} is an apocalyptic number.

21943659572836 is the 4684406-th square number.

It is an amenable number.

21943659572836 is a deficient number, since it is larger than the sum of its proper divisors (16457761075055).

21943659572836 is an frugal number, since it uses more digits than its factorization.

21943659572836 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4684410 (or 2342205 counting only the distinct ones).

The product of its digits is 587865600, while the sum is 70.

The spelling of 21943659572836 in words is "twenty-one trillion, nine hundred forty-three billion, six hundred fifty-nine million, five hundred seventy-two thousand, eight hundred thirty-six".