21745999231 has 8 divisors (see below), whose sum is σ = 23815218384. Its totient is φ = 19692165120.

The previous prime is 21745999217. The next prime is 21745999241. The reversal of 21745999231 is 13299954712.

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

It is a cyclic number.

It is not a de Polignac number, because 21745999231 - 2⁹ = 21745998719 is a prime.

It is a super-2 number, since 2×21745999231² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21745999241) 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, 3843300 + ... + 3848953.

It is an arithmetic number, because the mean of its divisors is an integer number (2976902298).

Almost surely, 2^21745999231 is an apocalyptic number.

21745999231 is a deficient number, since it is larger than the sum of its proper divisors (2069219153).

21745999231 is a wasteful number, since it uses less digits than its factorization.

21745999231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7692521.

The product of its digits is 1224720, while the sum is 52.

The spelling of 21745999231 in words is "twenty-one billion, seven hundred forty-five million, nine hundred ninety-nine thousand, two hundred thirty-one".