21861431942 has 64 divisors (see below), whose sum is σ = 39688704000. Its totient is φ = 8832983040.

The previous prime is 21861431941. The next prime is 21861431953. The reversal of 21861431942 is 24913416812.

It is a self number, because there is not a number n which added to its sum of digits gives 21861431942.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21861431941) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 8377934 + ... + 8380542.

It is an arithmetic number, because the mean of its divisors is an integer number (620136000).

Almost surely, 2^21861431942 is an apocalyptic number.

21861431942 is a deficient number, since it is larger than the sum of its proper divisors (17827272058).

21861431942 is a wasteful number, since it uses less digits than its factorization.

21861431942 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3141.

The product of its digits is 82944, while the sum is 41.

The spelling of 21861431942 in words is "twenty-one billion, eight hundred sixty-one million, four hundred thirty-one thousand, nine hundred forty-two".