21940861893 has 16 divisors (see below), whose sum is σ = 29998413312. Its totient is φ = 14256000000.

The previous prime is 21940861883. The next prime is 21940861907. The reversal of 21940861893 is 39816804912.

It is not a de Polignac number, because 21940861893 - 2¹⁶ = 21940796357 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21940861883) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 31893 + ... + 211893.

It is an arithmetic number, because the mean of its divisors is an integer number (1874900832).

Almost surely, 2^21940861893 is an apocalyptic number.

It is an amenable number.

21940861893 is a deficient number, since it is larger than the sum of its proper divisors (8057551419).

21940861893 is a wasteful number, since it uses less digits than its factorization.

21940861893 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 181036.

The product of its (nonzero) digits is 746496, while the sum is 51.

The spelling of 21940861893 in words is "twenty-one billion, nine hundred forty million, eight hundred sixty-one thousand, eight hundred ninety-three".