21542998 has 32 divisors (see below), whose sum is σ = 35704800. Its totient is φ = 9709056.

The previous prime is 21542993. The next prime is 21543001. The reversal of 21542998 is 89924512.

It is a self number, because there is not a number n which added to its sum of digits gives 21542998.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21542993) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 124440 + ... + 124612.

It is an arithmetic number, because the mean of its divisors is an integer number (1115775).

Almost surely, 2^21542998 is an apocalyptic number.

21542998 is a deficient number, since it is larger than the sum of its proper divisors (14161802).

21542998 is a wasteful number, since it uses less digits than its factorization.

21542998 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 336.

The product of its digits is 51840, while the sum is 40.

The square root of 21542998 is about 4641.4435254563. The cubic root of 21542998 is about 278.2501328603.

The spelling of 21542998 in words is "twenty-one million, five hundred forty-two thousand, nine hundred ninety-eight".