1230139749 has 4 divisors (see below), whose sum is σ = 1640186336. Its totient is φ = 820093164.

The previous prime is 1230139721. The next prime is 1230139759. The reversal of 1230139749 is 9479310321.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 1230139749 - 2²⁰ = 1229091173 is a prime.

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 (1230139709) 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, 205023289 + ... + 205023294.

It is an arithmetic number, because the mean of its divisors is an integer number (410046584).

Almost surely, 2^1230139749 is an apocalyptic number.

It is an amenable number.

1230139749 is a deficient number, since it is larger than the sum of its proper divisors (410046587).

1230139749 is an equidigital number, since it uses as much as digits as its factorization.

1230139749 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 410046586.

The product of its (nonzero) digits is 40824, while the sum is 39.

The square root of 1230139749 is about 35073.3481293132. The cubic root of 1230139749 is about 1071.4818461611.

The spelling of 1230139749 in words is "one billion, two hundred thirty million, one hundred thirty-nine thousand, seven hundred forty-nine".