21651426 has 12 divisors (see below), whose sum is σ = 46911462. Its totient is φ = 7217136.

The previous prime is 21651419. The next prime is 21651439. The reversal of 21651426 is 62415612.

21651426 is a `hidden beast` number, since 2 + 1 + 651 + 4 + 2 + 6 = 666.

It can be written as a sum of positive squares in only one way, i.e., 20930625 + 720801 = 4575^2 + 849^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 21651426.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 601411 + ... + 601446.

Almost surely, 2^21651426 is an apocalyptic number.

21651426 is an abundant number, since it is smaller than the sum of its proper divisors (25260036).

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

21651426 is a wasteful number, since it uses less digits than its factorization.

21651426 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1202865 (or 1202862 counting only the distinct ones).

The product of its digits is 2880, while the sum is 27.

The square root of 21651426 is about 4653.1092830493. The cubic root of 21651426 is about 278.7161718352.

The spelling of 21651426 in words is "twenty-one million, six hundred fifty-one thousand, four hundred twenty-six".