124399329781 has 4 divisors (see below), whose sum is σ = 124400035692. Its totient is φ = 124398623872.

The previous prime is 124399329757. The next prime is 124399329811. The reversal of 124399329781 is 187923993421.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 187923993421 = 1489 ⋅126208189.

It can be written as a sum of positive squares in 2 ways, for example, as 46818140625 + 77581189156 = 216375^2 + 278534^2 .

It is a cyclic number.

It is not a de Polignac number, because 124399329781 - 2²⁵ = 124365775349 is a prime.

It is a super-2 number, since 2×124399329781² (a number of 23 digits) contains 22 as substring.

It is a Smith number, since the sum of its digits (58) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (124399329751) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 156471 + ... + 522763.

It is an arithmetic number, because the mean of its divisors is an integer number (31100008923).

Almost surely, 2^124399329781 is an apocalyptic number.

It is an amenable number.

124399329781 is a deficient number, since it is larger than the sum of its proper divisors (705911).

124399329781 is an equidigital number, since it uses as much as digits as its factorization.

124399329781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 705910.

The product of its digits is 5878656, while the sum is 58.

The spelling of 124399329781 in words is "one hundred twenty-four billion, three hundred ninety-nine million, three hundred twenty-nine thousand, seven hundred eighty-one".