21730715 has 8 divisors (see below), whose sum is σ = 26976240. Its totient is φ = 16784992.

The previous prime is 21730693. The next prime is 21730727. The reversal of 21730715 is 51703712.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21730715 - 2⁸ = 21730459 is a prime.

It is a super-2 number, since 2×21730715² = 944447948822450, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 74789 + ... + 75078.

It is an arithmetic number, because the mean of its divisors is an integer number (3372030).

Almost surely, 2^21730715 is an apocalyptic number.

21730715 is a deficient number, since it is larger than the sum of its proper divisors (5245525).

21730715 is a wasteful number, since it uses less digits than its factorization.

21730715 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 149901.

The product of its (nonzero) digits is 1470, while the sum is 26.

The square root of 21730715 is about 4661.6214990065. The cubic root of 21730715 is about 279.0559832503.

The spelling of 21730715 in words is "twenty-one million, seven hundred thirty thousand, seven hundred fifteen".