21378642934 has 16 divisors (see below), whose sum is σ = 35084062656. Its totient is φ = 9689557000.

The previous prime is 21378642877. The next prime is 21378642973. The reversal of 21378642934 is 43924687312.

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 7 ways as a sum of consecutive naturals, for example, 1392592 + ... + 1407859.

It is an arithmetic number, because the mean of its divisors is an integer number (2192753916).

Almost surely, 2^21378642934 is an apocalyptic number.

21378642934 is a deficient number, since it is larger than the sum of its proper divisors (13705419722).

21378642934 is a wasteful number, since it uses less digits than its factorization.

21378642934 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2800811.

The product of its digits is 1741824, while the sum is 49.

The spelling of 21378642934 in words is "twenty-one billion, three hundred seventy-eight million, six hundred forty-two thousand, nine hundred thirty-four".