125381815981 has 4 divisors (see below), whose sum is σ = 125451051264. Its totient is φ = 125312580700.

The previous prime is 125381815957. The next prime is 125381815991. The reversal of 125381815981 is 189518183521.

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 a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-125381815981 is a prime.

It is a super-2 number, since 2×125381815981² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (125381815921) 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, 34614925 + ... + 34618546.

It is an arithmetic number, because the mean of its divisors is an integer number (31362762816).

Almost surely, 2^125381815981 is an apocalyptic number.

It is an amenable number.

125381815981 is a deficient number, since it is larger than the sum of its proper divisors (69235283).

125381815981 is an equidigital number, since it uses as much as digits as its factorization.

125381815981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 69235282.

The product of its digits is 691200, while the sum is 52.

The spelling of 125381815981 in words is "one hundred twenty-five billion, three hundred eighty-one million, eight hundred fifteen thousand, nine hundred eighty-one".