21130290 has 24 divisors (see below), whose sum is σ = 54938988. Its totient is φ = 5634720.

The previous prime is 21130279. The next prime is 21130301. The reversal of 21130290 is 9203112.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21130279) and next prime (21130301).

It can be written as a sum of positive squares in 2 ways, for example, as 19740249 + 1390041 = 4443^2 + 1179^2 .

It is a super-3 number, since 3×21130290³ (a number of 23 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 117301 + ... + 117480.

Almost surely, 2^21130290 is an apocalyptic number.

21130290 is an abundant number, since it is smaller than the sum of its proper divisors (33808698).

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

21130290 is a wasteful number, since it uses less digits than its factorization.

21130290 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 234794 (or 234791 counting only the distinct ones).

The product of its (nonzero) digits is 108, while the sum is 18.

The square root of 21130290 is about 4596.7695178244. The cubic root of 21130290 is about 276.4618134869.

The spelling of 21130290 in words is "twenty-one million, one hundred thirty thousand, two hundred ninety".