21316551431 has 8 divisors (see below), whose sum is σ = 24402860064. Its totient is φ = 18240514560.

The previous prime is 21316551427. The next prime is 21316551467. The reversal of 21316551431 is 13415561312.

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 21316551431 - 2² = 21316551427 is a prime.

It is a super-2 number, since 2×21316551431² (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 (21316556431) 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, 2563490 + ... + 2571791.

It is an arithmetic number, because the mean of its divisors is an integer number (3050357508).

Almost surely, 2^21316551431 is an apocalyptic number.

21316551431 is a deficient number, since it is larger than the sum of its proper divisors (3086308633).

21316551431 is an equidigital number, since it uses as much as digits as its factorization.

21316551431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5135881.

The product of its digits is 10800, while the sum is 32.

The spelling of 21316551431 in words is "twenty-one billion, three hundred sixteen million, five hundred fifty-one thousand, four hundred thirty-one".