21715502 has 4 divisors (see below), whose sum is σ = 32573256. Its totient is φ = 10857750.

The previous prime is 21715489. The next prime is 21715541. The reversal of 21715502 is 20551712.

It is a happy number.

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

It is a super-2 number, since 2×21715502² = 943126054224008, which contains 22 as substring.

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 as a sum of consecutive naturals, namely, 5428874 + ... + 5428877.

It is an arithmetic number, because the mean of its divisors is an integer number (8143314).

Almost surely, 2^21715502 is an apocalyptic number.

21715502 is a deficient number, since it is larger than the sum of its proper divisors (10857754).

21715502 is a wasteful number, since it uses less digits than its factorization.

21715502 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10857753.

The product of its (nonzero) digits is 700, while the sum is 23.

The square root of 21715502 is about 4659.9894849667. The cubic root of 21715502 is about 278.9908485670.

The spelling of 21715502 in words is "twenty-one million, seven hundred fifteen thousand, five hundred two".