21142156245 has 32 divisors (see below), whose sum is σ = 38695587840. Its totient is φ = 9656074560.

The previous prime is 21142156223. The next prime is 21142156253. The reversal of 21142156245 is 54265124112.

It is a happy number.

It is not a de Polignac number, because 21142156245 - 2²⁸ = 20873720789 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 22276 + ... + 206834.

It is an arithmetic number, because the mean of its divisors is an integer number (1209237120).

Almost surely, 2^21142156245 is an apocalyptic number.

It is an amenable number.

21142156245 is a deficient number, since it is larger than the sum of its proper divisors (17553431595).

21142156245 is a wasteful number, since it uses less digits than its factorization.

21142156245 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 185665.

The product of its digits is 19200, while the sum is 33.

The spelling of 21142156245 in words is "twenty-one billion, one hundred forty-two million, one hundred fifty-six thousand, two hundred forty-five".