21958461 has 12 divisors (see below), whose sum is σ = 36248992. Its totient is φ = 12547656.

The previous prime is 21958459. The next prime is 21958477. The reversal of 21958461 is 16485912.

21958461 is a `hidden beast` number, since 2 + 19 + 584 + 61 = 666.

It is not a de Polignac number, because 21958461 - 2¹ = 21958459 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21958421) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 174211 + ... + 174336.

Almost surely, 2^21958461 is an apocalyptic number.

21958461 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

21958461 is a deficient number, since it is larger than the sum of its proper divisors (14290531).

21958461 is a wasteful number, since it uses less digits than its factorization.

21958461 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 348560 (or 348557 counting only the distinct ones).

The product of its digits is 17280, while the sum is 36.

The square root of 21958461 is about 4685.9855953684. The cubic root of 21958461 is about 280.0274675435.

The spelling of 21958461 in words is "twenty-one million, nine hundred fifty-eight thousand, four hundred sixty-one".