21242310 has 32 divisors (see below), whose sum is σ = 51632640. Its totient is φ = 5592288.

The previous prime is 21242237. The next prime is 21242339. The reversal of 21242310 is 1324212.

It is a super-2 number, since 2×21242310² = 902471468272200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 21242310.

It is a congruent number.

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, 2112 + ... + 6851.

It is an arithmetic number, because the mean of its divisors is an integer number (1613520).

Almost surely, 2^21242310 is an apocalyptic number.

21242310 is an abundant number, since it is smaller than the sum of its proper divisors (30390330).

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

21242310 is a wasteful number, since it uses less digits than its factorization.

21242310 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9052.

The product of its (nonzero) digits is 96, while the sum is 15.

The square root of 21242310 is about 4608.9380555612. The cubic root of 21242310 is about 276.9494970638.

Adding to 21242310 its reverse (1324212), we get a palindrome (22566522).

The spelling of 21242310 in words is "twenty-one million, two hundred forty-two thousand, three hundred ten".