21342810 has 16 divisors (see below), whose sum is σ = 51222816. Its totient is φ = 5691408.

The previous prime is 21342809. The next prime is 21342817. The reversal of 21342810 is 1824312.

It is a super-2 number, since 2×21342810² = 911031077392200, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21342817) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 355684 + ... + 355743.

It is an arithmetic number, because the mean of its divisors is an integer number (3201426).

Almost surely, 2^21342810 is an apocalyptic number.

21342810 is an abundant number, since it is smaller than the sum of its proper divisors (29880006).

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

21342810 is a wasteful number, since it uses less digits than its factorization.

21342810 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 711437.

The product of its (nonzero) digits is 384, while the sum is 21.

The square root of 21342810 is about 4619.8279188732. The cubic root of 21342810 is about 277.3855708713.

The spelling of 21342810 in words is "twenty-one million, three hundred forty-two thousand, eight hundred ten".