21281850957 has 8 divisors (see below), whose sum is σ = 29142714976. Its totient is φ = 13804443792.

The previous prime is 21281850949. The next prime is 21281850959. The reversal of 21281850957 is 75905818212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21281850957 - 2³ = 21281850949 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21281850959) 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, 95864083 + ... + 95864304.

It is an arithmetic number, because the mean of its divisors is an integer number (3642839372).

Almost surely, 2^21281850957 is an apocalyptic number.

It is an amenable number.

21281850957 is a deficient number, since it is larger than the sum of its proper divisors (7860864019).

21281850957 is a wasteful number, since it uses less digits than its factorization.

21281850957 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 191728427.

The product of its (nonzero) digits is 403200, while the sum is 48.

The spelling of 21281850957 in words is "twenty-one billion, two hundred eighty-one million, eight hundred fifty thousand, nine hundred fifty-seven".