21742953281 has 8 divisors (see below), whose sum is σ = 24854485440. Its totient is φ = 18632770128.

The previous prime is 21742953209. The next prime is 21742953283. The reversal of 21742953281 is 18235924712.

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

It is not a de Polignac number, because 21742953281 - 2²⁶ = 21675844417 is a prime.

It is a super-2 number, since 2×21742953281² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21742953283) 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, 302471 + ... + 367388.

It is an arithmetic number, because the mean of its divisors is an integer number (3106810680).

Almost surely, 2^21742953281 is an apocalyptic number.

It is an amenable number.

21742953281 is a deficient number, since it is larger than the sum of its proper divisors (3111532159).

21742953281 is an equidigital number, since it uses as much as digits as its factorization.

21742953281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 674503.

The product of its digits is 241920, while the sum is 44.

The spelling of 21742953281 in words is "twenty-one billion, seven hundred forty-two million, nine hundred fifty-three thousand, two hundred eighty-one".