21415874 has 4 divisors (see below), whose sum is σ = 32123814. Its totient is φ = 10707936.

The previous prime is 21415871. The next prime is 21415931. The reversal of 21415874 is 47851412.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 21298225 + 117649 = 4615^2 + 343^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 21415874.

It is not an unprimeable number, because it can be changed into a prime (21415871) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5353967 + ... + 5353970.

Almost surely, 2^21415874 is an apocalyptic number.

21415874 is a deficient number, since it is larger than the sum of its proper divisors (10707940).

21415874 is a wasteful number, since it uses less digits than its factorization.

21415874 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10707939.

The product of its digits is 8960, while the sum is 32.

The square root of 21415874 is about 4627.7288166011. The cubic root of 21415874 is about 277.7017400528.

The spelling of 21415874 in words is "twenty-one million, four hundred fifteen thousand, eight hundred seventy-four".