21617492 has 12 divisors (see below), whose sum is σ = 40740756. Its totient is φ = 9977280.

The previous prime is 21617461. The next prime is 21617501. The reversal of 21617492 is 29471612.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 1223236 + 20394256 = 1106^2 + 4516^2 .

It is a congruent number.

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 3 ways as a sum of consecutive naturals, for example, 207809 + ... + 207912.

It is an arithmetic number, because the mean of its divisors is an integer number (3395063).

Almost surely, 2^21617492 is an apocalyptic number.

It is an amenable number.

21617492 is a deficient number, since it is larger than the sum of its proper divisors (19123264).

21617492 is a wasteful number, since it uses less digits than its factorization.

21617492 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 415738 (or 415736 counting only the distinct ones).

The product of its digits is 6048, while the sum is 32.

The square root of 21617492 is about 4649.4614741925. The cubic root of 21617492 is about 278.5704862809.

The spelling of 21617492 in words is "twenty-one million, six hundred seventeen thousand, four hundred ninety-two".