21613976 has 16 divisors (see below), whose sum is σ = 40575600. Its totient is φ = 10793824.

The previous prime is 21613973. The next prime is 21613981. The reversal of 21613976 is 67931612.

It is a plaindrome in base 11.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21613973) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11606 + ... + 13338.

It is an arithmetic number, because the mean of its divisors is an integer number (2535975).

Almost surely, 2^21613976 is an apocalyptic number.

It is an amenable number.

21613976 is a deficient number, since it is larger than the sum of its proper divisors (18961624).

21613976 is a wasteful number, since it uses less digits than its factorization.

21613976 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3298 (or 3294 counting only the distinct ones).

The product of its digits is 13608, while the sum is 35.

The square root of 21613976 is about 4649.0833505112. The cubic root of 21613976 is about 278.5553826643. Note that the first 3 decimals are identical.

The spelling of 21613976 in words is "twenty-one million, six hundred thirteen thousand, nine hundred seventy-six".