21079290 has 32 divisors (see below), whose sum is σ = 50714496. Its totient is φ = 5607360.

The previous prime is 21079271. The next prime is 21079297. The reversal of 21079290 is 9297012.

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

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21079297) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 19299 + ... + 20361.

It is an arithmetic number, because the mean of its divisors is an integer number (1584828).

Almost surely, 2^21079290 is an apocalyptic number.

21079290 is an abundant number, since it is smaller than the sum of its proper divisors (29635206).

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

21079290 is a wasteful number, since it uses less digits than its factorization.

21079290 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1734.

The product of its (nonzero) digits is 2268, while the sum is 30.

The square root of 21079290 is about 4591.2187924341. The cubic root of 21079290 is about 276.2392118525.

The spelling of 21079290 in words is "twenty-one million, seventy-nine thousand, two hundred ninety".