21931142 has 8 divisors (see below), whose sum is σ = 33133800. Its totient is φ = 10886544.

The previous prime is 21931141. The next prime is 21931157. The reversal of 21931142 is 24113912.

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 (21931141) 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, 39167 + ... + 39722.

It is an arithmetic number, because the mean of its divisors is an integer number (4141725).

Almost surely, 2^21931142 is an apocalyptic number.

21931142 is a deficient number, since it is larger than the sum of its proper divisors (11202658).

21931142 is a wasteful number, since it uses less digits than its factorization.

21931142 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 79030.

The product of its digits is 432, while the sum is 23.

The square root of 21931142 is about 4683.0697197458. The cubic root of 21931142 is about 279.9112899249.

The spelling of 21931142 in words is "twenty-one million, nine hundred thirty-one thousand, one hundred forty-two".