21965130 has 72 divisors (see below), whose sum is σ = 62804196. Its totient is φ = 5322240.

The previous prime is 21965117. The next prime is 21965149. The reversal of 21965130 is 3156912.

21965130 is a `hidden beast` number, since 2 + 1 + 9 + 651 + 3 + 0 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 21650409 + 314721 = 4653^2 + 561^2 .

It is a Smith number, since the sum of its digits (27) coincides with the sum of the digits of its prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 21965094 and 21965103.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 9882 + ... + 11898.

Almost surely, 2^21965130 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21965130, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31402098).

21965130 is an abundant number, since it is smaller than the sum of its proper divisors (40839066).

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

21965130 is a wasteful number, since it uses less digits than its factorization.

21965130 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2052 (or 2038 counting only the distinct ones).

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

The square root of 21965130 is about 4686.6971312429. The cubic root of 21965130 is about 280.0558137036.

The spelling of 21965130 in words is "twenty-one million, nine hundred sixty-five thousand, one hundred thirty".