21113978942 has 32 divisors (see below), whose sum is σ = 36910556928. Its totient is φ = 8871803136.

The previous prime is 21113978939. The next prime is 21113979011. The reversal of 21113978942 is 24987931112.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 72653 + ... + 217959.

It is an arithmetic number, because the mean of its divisors is an integer number (1153454904).

Almost surely, 2^21113978942 is an apocalyptic number.

It is a pronic number, being equal to 145306×145307.

21113978942 is a deficient number, since it is larger than the sum of its proper divisors (15796577986).

21113978942 is a wasteful number, since it uses less digits than its factorization.

21113978942 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 145520.

The product of its digits is 217728, while the sum is 47.

The spelling of 21113978942 in words is "twenty-one billion, one hundred thirteen million, nine hundred seventy-eight thousand, nine hundred forty-two".