21402174 has 16 divisors (see below), whose sum is σ = 44280720. Its totient is φ = 6888000.

The previous prime is 21402163. The next prime is 21402181. The reversal of 21402174 is 47120412.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 21402174.

It is a congruent number.

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, 61327 + ... + 61674.

It is an arithmetic number, because the mean of its divisors is an integer number (2767545).

Almost surely, 2^21402174 is an apocalyptic number.

21402174 is an abundant number, since it is smaller than the sum of its proper divisors (22878546).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21402174 is a wasteful number, since it uses less digits than its factorization.

21402174 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 123035.

The product of its (nonzero) digits is 448, while the sum is 21.

The square root of 21402174 is about 4626.2483720613. The cubic root of 21402174 is about 277.6425110063.

Subtracting from 21402174 its sum of digits (21), we obtain a triangular number (21402153 = T₆₅₄₂).

Adding to 21402174 its reverse (47120412), we get a palindrome (68522586).

The spelling of 21402174 in words is "twenty-one million, four hundred two thousand, one hundred seventy-four".