21070715 has 8 divisors (see below), whose sum is σ = 26615760. Its totient is φ = 15969312.

The previous prime is 21070703. The next prime is 21070727. The reversal of 21070715 is 51707012.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21070703) and next prime (21070727).

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21070715 is a prime.

It is a super-2 number, since 2×21070715² = 887950061222450, 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, 110804 + ... + 110993.

It is an arithmetic number, because the mean of its divisors is an integer number (3326970).

Almost surely, 2^21070715 is an apocalyptic number.

21070715 is a deficient number, since it is larger than the sum of its proper divisors (5545045).

21070715 is a wasteful number, since it uses less digits than its factorization.

21070715 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 221821.

The product of its (nonzero) digits is 490, while the sum is 23.

The square root of 21070715 is about 4590.2848495491. The cubic root of 21070715 is about 276.2017489760.

Adding to 21070715 its reverse (51707012), we get a palindrome (72777727).

The spelling of 21070715 in words is "twenty-one million, seventy thousand, seven hundred fifteen".