21929284 has 12 divisors (see below), whose sum is σ = 41328364. Its totient is φ = 10121184.

The previous prime is 21929267. The next prime is 21929293. The reversal of 21929284 is 48292912.

It can be written as a sum of positive squares in 2 ways, for example, as 6874884 + 15054400 = 2622^2 + 3880^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 210807 + ... + 210910.

Almost surely, 2^21929284 is an apocalyptic number.

It is an amenable number.

21929284 is a deficient number, since it is larger than the sum of its proper divisors (19399080).

21929284 is a wasteful number, since it uses less digits than its factorization.

21929284 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 421734 (or 421732 counting only the distinct ones).

The product of its digits is 20736, while the sum is 37.

The square root of 21929284 is about 4682.8713413887. The cubic root of 21929284 is about 279.9033850339.

It can be divided in two parts, 2192 and 9284, that added together give a triangular number (11476 = T₁₅₁).

The spelling of 21929284 in words is "twenty-one million, nine hundred twenty-nine thousand, two hundred eighty-four".