21461790 has 32 divisors (see below), whose sum is σ = 58867200. Its totient is φ = 4905504.

The previous prime is 21461789. The next prime is 21461821. The reversal of 21461790 is 9716412.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 50890 + ... + 51309.

It is an arithmetic number, because the mean of its divisors is an integer number (1839600).

Almost surely, 2^21461790 is an apocalyptic number.

21461790 is an abundant number, since it is smaller than the sum of its proper divisors (37405410).

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

21461790 is a wasteful number, since it uses less digits than its factorization.

21461790 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 102216.

The product of its (nonzero) digits is 3024, while the sum is 30.

The square root of 21461790 is about 4632.6871252007. The cubic root of 21461790 is about 277.9000641430.

The spelling of 21461790 in words is "twenty-one million, four hundred sixty-one thousand, seven hundred ninety".