21402312 has 16 divisors (see below), whose sum is σ = 53505840. Its totient is φ = 7134096.

The previous prime is 21402299. The next prime is 21402323. The reversal of 21402312 is 21320412.

It is a junction number, because it is equal to n+sod(n) for n = 21402291 and 21402300.

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, 445858 + ... + 445905.

It is an arithmetic number, because the mean of its divisors is an integer number (3344115).

Almost surely, 2^21402312 is an apocalyptic number.

It is an amenable number.

21402312 is an abundant number, since it is smaller than the sum of its proper divisors (32103528).

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

21402312 is a wasteful number, since it uses less digits than its factorization.

21402312 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 891772 (or 891768 counting only the distinct ones).

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

The square root of 21402312 is about 4626.2632869304. The cubic root of 21402312 is about 277.6431077461.

Adding to 21402312 its reverse (21320412), we get a palindrome (42722724).

The spelling of 21402312 in words is "twenty-one million, four hundred two thousand, three hundred twelve".