21598461 has 16 divisors (see below), whose sum is σ = 32236800. Its totient is φ = 14291424.

The previous prime is 21598457. The next prime is 21598463. The reversal of 21598461 is 16489512.

21598461 is a `hidden beast` number, since 2 + 1 + 598 + 4 + 61 = 666.

It is not a de Polignac number, because 21598461 - 2² = 21598457 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21598463) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 780 + ... + 6618.

It is an arithmetic number, because the mean of its divisors is an integer number (2014800).

Almost surely, 2^21598461 is an apocalyptic number.

It is an amenable number.

21598461 is a deficient number, since it is larger than the sum of its proper divisors (10638339).

21598461 is a wasteful number, since it uses less digits than its factorization.

21598461 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5985 (or 5979 counting only the distinct ones).

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

The square root of 21598461 is about 4647.4144424615. The cubic root of 21598461 is about 278.4887155956.

The spelling of 21598461 in words is "twenty-one million, five hundred ninety-eight thousand, four hundred sixty-one".