21292518 has 16 divisors (see below), whose sum is σ = 45860976. Its totient is φ = 6551520.

The previous prime is 21292507. The next prime is 21292519. The reversal of 21292518 is 81529212.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21292519) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 136413 + ... + 136568.

It is an arithmetic number, because the mean of its divisors is an integer number (2866311).

Almost surely, 2^21292518 is an apocalyptic number.

21292518 is an abundant number, since it is smaller than the sum of its proper divisors (24568458).

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

21292518 is a wasteful number, since it uses less digits than its factorization.

21292518 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 272999.

The product of its digits is 2880, while the sum is 30.

The square root of 21292518 is about 4614.3816487152. The cubic root of 21292518 is about 277.1675232488.

The spelling of 21292518 in words is "twenty-one million, two hundred ninety-two thousand, five hundred eighteen".