21492068 has 18 divisors (see below), whose sum is σ = 40728114. Its totient is φ = 9919104.

The previous prime is 21492067. The next prime is 21492151. The reversal of 21492068 is 86029412.

It can be written as a sum of positive squares in 3 ways, for example, as 350464 + 21141604 = 592^2 + 4598^2 .

It is not an unprimeable number, because it can be changed into a prime (21492061) 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 5 ways as a sum of consecutive naturals, for example, 15221 + ... + 16572.

It is an arithmetic number, because the mean of its divisors is an integer number (2262673).

Almost surely, 2^21492068 is an apocalyptic number.

It is an amenable number.

21492068 is a deficient number, since it is larger than the sum of its proper divisors (19236046).

21492068 is a wasteful number, since it uses less digits than its factorization.

21492068 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31823 (or 31808 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 32.

The square root of 21492068 is about 4635.9538392870. The cubic root of 21492068 is about 278.0306886053.

The spelling of 21492068 in words is "twenty-one million, four hundred ninety-two thousand, sixty-eight".