125919440639 has 4 divisors (see below), whose sum is σ = 132546779640. Its totient is φ = 119292101640.

The previous prime is 125919440627. The next prime is 125919440651. The reversal of 125919440639 is 936044919521.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 936044919521 = 109 ⋅8587568069.

It is an interprime number because it is at equal distance from previous prime (125919440627) and next prime (125919440651).

It is a cyclic number.

It is not a de Polignac number, because 125919440639 - 2¹⁶ = 125919375103 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (125919440239) 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, 3313669472 + ... + 3313669509.

It is an arithmetic number, because the mean of its divisors is an integer number (33136694910).

Almost surely, 2^125919440639 is an apocalyptic number.

125919440639 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

125919440639 is a deficient number, since it is larger than the sum of its proper divisors (6627339001).

125919440639 is an equidigital number, since it uses as much as digits as its factorization.

125919440639 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6627339000.

The product of its (nonzero) digits is 2099520, while the sum is 53.

The spelling of 125919440639 in words is "one hundred twenty-five billion, nine hundred nineteen million, four hundred forty thousand, six hundred thirty-nine".