21457142 has 16 divisors (see below), whose sum is σ = 36864672. Its totient is φ = 9175680.

The previous prime is 21457141. The next prime is 21457153. The reversal of 21457142 is 24175412.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21457141) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6158 + ... + 8990.

It is an arithmetic number, because the mean of its divisors is an integer number (2304042).

Almost surely, 2^21457142 is an apocalyptic number.

21457142 is a deficient number, since it is larger than the sum of its proper divisors (15407530).

21457142 is a wasteful number, since it uses less digits than its factorization.

21457142 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3383.

The product of its digits is 2240, while the sum is 26.

The square root of 21457142 is about 4632.1854453379. The cubic root of 21457142 is about 277.8800010021.

The spelling of 21457142 in words is "twenty-one million, four hundred fifty-seven thousand, one hundred forty-two".