21541255531 has 8 divisors (see below), whose sum is σ = 21786766560. Its totient is φ = 21295821888.

The previous prime is 21541255511. The next prime is 21541255579. The reversal of 21541255531 is 13555214512.

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 21541255531 - 2⁷ = 21541255403 is a prime.

It is a super-2 number, since 2×21541255531² (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 (21541255501) 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, 685690 + ... + 716416.

It is an arithmetic number, because the mean of its divisors is an integer number (2723345820).

Almost surely, 2^21541255531 is an apocalyptic number.

21541255531 is a deficient number, since it is larger than the sum of its proper divisors (245511029).

21541255531 is an equidigital number, since it uses as much as digits as its factorization.

21541255531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38693.

The product of its digits is 30000, while the sum is 34.

The spelling of 21541255531 in words is "twenty-one billion, five hundred forty-one million, two hundred fifty-five thousand, five hundred thirty-one".