21878374 has 16 divisors (see below), whose sum is σ = 38716416. Its totient is φ = 9073800.

The previous prime is 21878369. The next prime is 21878401. The reversal of 21878374 is 47387812.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 24772 + ... + 25639.

It is an arithmetic number, because the mean of its divisors is an integer number (2419776).

Almost surely, 2^21878374 is an apocalyptic number.

21878374 is a deficient number, since it is larger than the sum of its proper divisors (16838042).

21878374 is a wasteful number, since it uses less digits than its factorization.

21878374 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 50451.

The product of its digits is 75264, while the sum is 40.

The square root of 21878374 is about 4677.4324153322. The cubic root of 21878374 is about 279.6866136630.

The spelling of 21878374 in words is "twenty-one million, eight hundred seventy-eight thousand, three hundred seventy-four".