21916515 has 8 divisors (see below), whose sum is σ = 35066448. Its totient is φ = 11688800.

The previous prime is 21916513. The next prime is 21916529. The reversal of 21916515 is 51561912.

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

It is not a de Polignac number, because 21916515 - 2¹ = 21916513 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21916511) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 730536 + ... + 730565.

It is an arithmetic number, because the mean of its divisors is an integer number (4383306).

Almost surely, 2^21916515 is an apocalyptic number.

21916515 is a deficient number, since it is larger than the sum of its proper divisors (13149933).

21916515 is a wasteful number, since it uses less digits than its factorization.

21916515 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1461109.

The product of its digits is 2700, while the sum is 30.

The square root of 21916515 is about 4681.5077699391. The cubic root of 21916515 is about 279.8490470346.

The spelling of 21916515 in words is "twenty-one million, nine hundred sixteen thousand, five hundred fifteen".