123992981 has 6 divisors (see below), whose sum is σ = 144236790. Its totient is φ = 106279656.

The previous prime is 123992971. The next prime is 123992989. The reversal of 123992981 is 189299321.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 115756081 + 8236900 = 10759^2 + 2870^2 .

It is not a de Polignac number, because 123992981 - 2²⁶ = 56884117 is a prime.

It is a super-2 number, since 2×123992981² = 30748518674532722, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (123992989) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1265186 + ... + 1265283.

It is an arithmetic number, because the mean of its divisors is an integer number (24039465).

Almost surely, 2^123992981 is an apocalyptic number.

It is an amenable number.

123992981 is a deficient number, since it is larger than the sum of its proper divisors (20243809).

123992981 is an equidigital number, since it uses as much as digits as its factorization.

123992981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2530483 (or 2530476 counting only the distinct ones).

The product of its digits is 69984, while the sum is 44.

The square root of 123992981 is about 11135.2135587963. The cubic root of 123992981 is about 498.6536861316.

It can be divided in two parts, 12 and 3992981, that added together give a palindrome (3992993).

The spelling of 123992981 in words is "one hundred twenty-three million, nine hundred ninety-two thousand, nine hundred eighty-one".