21358774 has 16 divisors (see below), whose sum is σ = 34444800. Its totient is φ = 9901224.

The previous prime is 21358747. The next prime is 21358781. The reversal of 21358774 is 47785312.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4194 + ... + 7765.

It is an arithmetic number, because the mean of its divisors is an integer number (2152800).

Almost surely, 2^21358774 is an apocalyptic number.

21358774 is a deficient number, since it is larger than the sum of its proper divisors (13086026).

21358774 is a wasteful number, since it uses less digits than its factorization.

21358774 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12027.

The product of its digits is 47040, while the sum is 37.

The square root of 21358774 is about 4621.5553658914. Note that the first 3 decimals coincide. The cubic root of 21358774 is about 277.4547132764.

It can be divided in two parts, 2 and 1358774, that added together give a triangular number (1358776 = T₁₆₄₈).

The spelling of 21358774 in words is "twenty-one million, three hundred fifty-eight thousand, seven hundred seventy-four".