21617494 has 4 divisors (see below), whose sum is σ = 32426244. Its totient is φ = 10808746.

The previous prime is 21617461. The next prime is 21617501. The reversal of 21617494 is 49471612.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5404372 + ... + 5404375.

It is an arithmetic number, because the mean of its divisors is an integer number (8106561).

Almost surely, 2^21617494 is an apocalyptic number.

21617494 is a deficient number, since it is larger than the sum of its proper divisors (10808750).

21617494 is a wasteful number, since it uses less digits than its factorization.

21617494 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10808749.

The product of its digits is 12096, while the sum is 34.

The square root of 21617494 is about 4649.4616892711. The cubic root of 21617494 is about 278.5704948718.

The spelling of 21617494 in words is "twenty-one million, six hundred seventeen thousand, four hundred ninety-four".