231630919681 has 64 divisors (see below), whose sum is σ = 281601802240. Its totient is φ = 186386987520.

The previous prime is 231630919679. The next prime is 231630919687. The reversal of 231630919681 is 186919036132.

It is a 12-Lehmer number, since φ(231630919681) divides (231630919681-1)¹².

It is a cyclic number.

It is not a de Polignac number, because 231630919681 - 2¹ = 231630919679 is a prime.

It is a super-2 number, since 2×231630919681² (a number of 24 digits) contains 22 as substring.

It is the 481281-st Hogben number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (231630919687) by changing a digit.

It is a nontrivial repunit in base 481280.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 281446636 + ... + 281447458.

It is an arithmetic number, because the mean of its divisors is an integer number (4400028160).

Almost surely, 2^231630919681 is an apocalyptic number.

It is an amenable number.

231630919681 is a deficient number, since it is larger than the sum of its proper divisors (49970882559).

231630919681 is a wasteful number, since it uses less digits than its factorization.

231630919681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1206.

The product of its (nonzero) digits is 419904, while the sum is 49.

The spelling of 231630919681 in words is "two hundred thirty-one billion, six hundred thirty million, nine hundred nineteen thousand, six hundred eighty-one".