21790474 has 16 divisors (see below), whose sum is σ = 33284160. Its totient is φ = 10697760.

The previous prime is 21790471. The next prime is 21790487. The reversal of 21790474 is 47409712.

21790474 = T₄₈₉ + T₄₉₀ + ... + T₆₂₇.

It is not an unprimeable number, because it can be changed into a prime (21790471) by changing a digit.

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, 28254 + ... + 29014.

It is an arithmetic number, because the mean of its divisors is an integer number (2080260).

Almost surely, 2^21790474 is an apocalyptic number.

21790474 is a deficient number, since it is larger than the sum of its proper divisors (11493686).

21790474 is a wasteful number, since it uses less digits than its factorization.

21790474 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1005.

The product of its (nonzero) digits is 14112, while the sum is 34.

The square root of 21790474 is about 4668.0267779866. The cubic root of 21790474 is about 279.3115484492.

The spelling of 21790474 in words is "twenty-one million, seven hundred ninety thousand, four hundred seventy-four".