21572342 has 32 divisors (see below), whose sum is σ = 37269504. Its totient is φ = 9273600.

The previous prime is 21572339. The next prime is 21572359. The reversal of 21572342 is 24327512.

It is a congruent number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 31718 + ... + 32390.

It is an arithmetic number, because the mean of its divisors is an integer number (1164672).

Almost surely, 2^21572342 is an apocalyptic number.

21572342 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

21572342 is a deficient number, since it is larger than the sum of its proper divisors (15697162).

21572342 is a wasteful number, since it uses less digits than its factorization.

21572342 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 764.

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

The square root of 21572342 is about 4644.6035352869. The cubic root of 21572342 is about 278.3764115936.

Adding to 21572342 its reverse (24327512), we get a palindrome (45899854).

The spelling of 21572342 in words is "twenty-one million, five hundred seventy-two thousand, three hundred forty-two".