21890330 has 32 divisors (see below), whose sum is σ = 49127040. Its totient is φ = 6822720.

The previous prime is 21890329. The next prime is 21890369. The reversal of 21890330 is 3309812.

It is a self number, because there is not a number n which added to its sum of digits gives 21890330.

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, 13445 + ... + 14984.

It is an arithmetic number, because the mean of its divisors is an integer number (1535220).

Almost surely, 2^21890330 is an apocalyptic number.

21890330 is an abundant number, since it is smaller than the sum of its proper divisors (27236710).

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

21890330 is a wasteful number, since it uses less digits than its factorization.

21890330 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28454.

The product of its (nonzero) digits is 1296, while the sum is 26.

The square root of 21890330 is about 4678.7102923776. The cubic root of 21890330 is about 279.7375516991.

The spelling of 21890330 in words is "twenty-one million, eight hundred ninety thousand, three hundred thirty".