21426916 has 18 divisors (see below), whose sum is σ = 43619478. Its totient is φ = 9182880.

The previous prime is 21426907. The next prime is 21426929. The reversal of 21426916 is 61962412.

It can be written as a sum of positive squares in only one way, i.e., 17640000 + 3786916 = 4200^2 + 1946^2 .

It is a super-2 number, since 2×21426916² = 918225458542112, which contains 22 as substring.

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 5 ways as a sum of consecutive naturals, for example, 54465 + ... + 54856.

Almost surely, 2^21426916 is an apocalyptic number.

It is an amenable number.

21426916 is an abundant number, since it is smaller than the sum of its proper divisors (22192562).

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

21426916 is a wasteful number, since it uses less digits than its factorization.

21426916 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 109339 (or 109330 counting only the distinct ones).

The product of its digits is 5184, while the sum is 31.

The square root of 21426916 is about 4628.9216886873. The cubic root of 21426916 is about 277.7494594183.

The spelling of 21426916 in words is "twenty-one million, four hundred twenty-six thousand, nine hundred sixteen".