21474915 has 32 divisors (see below), whose sum is σ = 42840576. Its totient is φ = 8924160.

The previous prime is 21474913. The next prime is 21474919. The reversal of 21474915 is 51947412.

It is a happy number.

It is not a de Polignac number, because 21474915 - 2¹ = 21474913 is a prime.

It is a super-2 number, since 2×21474915² = 922343948514450, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is not an unprimeable number, because it can be changed into a prime (21474913) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 8142 + ... + 10451.

It is an arithmetic number, because the mean of its divisors is an integer number (1338768).

Almost surely, 2^21474915 is an apocalyptic number.

21474915 is a deficient number, since it is larger than the sum of its proper divisors (21365661).

21474915 is a wasteful number, since it uses less digits than its factorization.

21474915 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18619.

The product of its digits is 10080, while the sum is 33.

The square root of 21474915 is about 4634.1034731650. The cubic root of 21474915 is about 277.9567027096.

The spelling of 21474915 in words is "twenty-one million, four hundred seventy-four thousand, nine hundred fifteen".