21130956 has 180 divisors, whose sum is σ = 70680456. Its totient is φ = 5488560.

The previous prime is 21130939. The next prime is 21130961. The reversal of 21130956 is 65903112.

It is a powerful number, because all its prime factors have an exponent greater than 1 and also an Achilles number because it is not a perfect power.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

It is a polite number, since it can be written in 59 ways as a sum of consecutive naturals, for example, 1920991 + ... + 1921001.

Almost surely, 2^21130956 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21130956, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35340228).

21130956 is an abundant number, since it is smaller than the sum of its proper divisors (49549500).

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

21130956 is a wasteful number, since it uses less digits than its factorization.

21130956 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 63 (or 23 counting only the distinct ones).

The product of its (nonzero) digits is 1620, while the sum is 27.

The square root of 21130956 is about 4596.8419594326. The cubic root of 21130956 is about 276.4647180319.

The spelling of 21130956 in words is "twenty-one million, one hundred thirty thousand, nine hundred fifty-six".