125561321437 has 4 divisors (see below), whose sum is σ = 125575458976. Its totient is φ = 125547183900.

The previous prime is 125561321407. The next prime is 125561321453. The reversal of 125561321437 is 734123165521.

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 not a de Polignac number, because 125561321437 - 2¹⁹ = 125560797149 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 125561321437.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (125561321407) 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, 7055439 + ... + 7073212.

It is an arithmetic number, because the mean of its divisors is an integer number (31393864744).

Almost surely, 2^125561321437 is an apocalyptic number.

It is an amenable number.

125561321437 is a deficient number, since it is larger than the sum of its proper divisors (14137539).

125561321437 is an equidigital number, since it uses as much as digits as its factorization.

125561321437 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14137538.

The product of its digits is 151200, while the sum is 40.

Adding to 125561321437 its reverse (734123165521), we get a palindrome (859684486958).

The spelling of 125561321437 in words is "one hundred twenty-five billion, five hundred sixty-one million, three hundred twenty-one thousand, four hundred thirty-seven".