21620174 has 4 divisors (see below), whose sum is σ = 32430264. Its totient is φ = 10810086.

The previous prime is 21620153. The next prime is 21620189. The reversal of 21620174 is 47102612.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5405042 + ... + 5405045.

It is an arithmetic number, because the mean of its divisors is an integer number (8107566).

Almost surely, 2^21620174 is an apocalyptic number.

21620174 is a deficient number, since it is larger than the sum of its proper divisors (10810090).

21620174 is a wasteful number, since it uses less digits than its factorization.

21620174 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10810089.

The product of its (nonzero) digits is 672, while the sum is 23.

The square root of 21620174 is about 4649.7498857465. The cubic root of 21620174 is about 278.5820061980.

Adding to 21620174 its reverse (47102612), we get a palindrome (68722786).

The spelling of 21620174 in words is "twenty-one million, six hundred twenty thousand, one hundred seventy-four".