21630442 has 8 divisors (see below), whose sum is σ = 33856416. Its totient is φ = 10344972.

The previous prime is 21630439. The next prime is 21630451. The reversal of 21630442 is 24403612.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×21630442² = 935752042230728, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 235068 + ... + 235159.

It is an arithmetic number, because the mean of its divisors is an integer number (4232052).

Almost surely, 2^21630442 is an apocalyptic number.

21630442 is a deficient number, since it is larger than the sum of its proper divisors (12225974).

21630442 is a wasteful number, since it uses less digits than its factorization.

21630442 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 470252.

The product of its (nonzero) digits is 1152, while the sum is 22.

The square root of 21630442 is about 4650.8539000919. The cubic root of 21630442 is about 278.6261012381.

The spelling of 21630442 in words is "twenty-one million, six hundred thirty thousand, four hundred forty-two".