21142372 has 12 divisors (see below), whose sum is σ = 38192896. Its totient is φ = 10230120.

The previous prime is 21142361. The next prime is 21142379. The reversal of 21142372 is 27324112.

It is a hoax number, since the sum of its digits (22) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (21142379) 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 3 ways as a sum of consecutive naturals, for example, 85128 + ... + 85375.

Almost surely, 2^21142372 is an apocalyptic number.

It is an amenable number.

21142372 is a deficient number, since it is larger than the sum of its proper divisors (17050524).

21142372 is a wasteful number, since it uses less digits than its factorization.

21142372 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 170538 (or 170536 counting only the distinct ones).

The product of its digits is 672, while the sum is 22.

The square root of 21142372 is about 4598.0835138131. The cubic root of 21142372 is about 276.5144957613.

Adding to 21142372 its reverse (27324112), we get a palindrome (48466484).

The spelling of 21142372 in words is "twenty-one million, one hundred forty-two thousand, three hundred seventy-two".