21787074 has 12 divisors (see below), whose sum is σ = 47205366. Its totient is φ = 7262352.

The previous prime is 21787067. The next prime is 21787097. The reversal of 21787074 is 47078712.

It can be written as a sum of positive squares in only one way, i.e., 20115225 + 1671849 = 4485^2 + 1293^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 605179 + ... + 605214.

Almost surely, 2^21787074 is an apocalyptic number.

21787074 is an abundant number, since it is smaller than the sum of its proper divisors (25418292).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21787074 is a wasteful number, since it uses less digits than its factorization.

21787074 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1210401 (or 1210398 counting only the distinct ones).

The product of its (nonzero) digits is 21952, while the sum is 36.

The square root of 21787074 is about 4667.6625842064. The cubic root of 21787074 is about 279.2970205617.

The spelling of 21787074 in words is "twenty-one million, seven hundred eighty-seven thousand, seventy-four".