21557731343 has 16 divisors (see below), whose sum is σ = 22062028800. Its totient is φ = 21058440480.

The previous prime is 21557731339. The next prime is 21557731357. The reversal of 21557731343 is 34313775512.

It is not a de Polignac number, because 21557731343 - 2² = 21557731339 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21557731343.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21557731313) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9327158 + ... + 9329468.

It is an arithmetic number, because the mean of its divisors is an integer number (1378876800).

Almost surely, 2^21557731343 is an apocalyptic number.

21557731343 is a deficient number, since it is larger than the sum of its proper divisors (504297457).

21557731343 is a wasteful number, since it uses less digits than its factorization.

21557731343 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3302.

The product of its digits is 264600, while the sum is 41.

The spelling of 21557731343 in words is "twenty-one billion, five hundred fifty-seven million, seven hundred thirty-one thousand, three hundred forty-three".