21372542 has 8 divisors (see below), whose sum is σ = 32162832. Its totient is φ = 10651600.

The previous prime is 21372541. The next prime is 21372551. The reversal of 21372542 is 24527312.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21372541) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16559 + ... + 17802.

It is an arithmetic number, because the mean of its divisors is an integer number (4020354).

Almost surely, 2^21372542 is an apocalyptic number.

21372542 is a deficient number, since it is larger than the sum of its proper divisors (10790290).

21372542 is a wasteful number, since it uses less digits than its factorization.

21372542 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34674.

The product of its digits is 3360, while the sum is 26.

The square root of 21372542 is about 4623.0446677487. The cubic root of 21372542 is about 277.5143168222.

Adding to 21372542 its reverse (24527312), we get a palindrome (45899854).

The spelling of 21372542 in words is "twenty-one million, three hundred seventy-two thousand, five hundred forty-two".