21942915 has 8 divisors (see below), whose sum is σ = 35108688. Its totient is φ = 11702880.

The previous prime is 21942911. The next prime is 21942919. The reversal of 21942915 is 51924912.

It is an interprime number because it is at equal distance from previous prime (21942911) and next prime (21942919).

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

It is not a de Polignac number, because 21942915 - 2² = 21942911 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21942911) 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, 731416 + ... + 731445.

It is an arithmetic number, because the mean of its divisors is an integer number (4388586).

Almost surely, 2^21942915 is an apocalyptic number.

21942915 is a deficient number, since it is larger than the sum of its proper divisors (13165773).

21942915 is a wasteful number, since it uses less digits than its factorization.

21942915 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1462869.

The product of its digits is 6480, while the sum is 33.

The square root of 21942915 is about 4684.3265257665. The cubic root of 21942915 is about 279.9613679694.

It can be divided in two parts, 219 and 42915, that added together give a palindrome (43134).

The spelling of 21942915 in words is "twenty-one million, nine hundred forty-two thousand, nine hundred fifteen".