125521961 has 4 divisors (see below), whose sum is σ = 132128400. Its totient is φ = 118915524.

The previous prime is 125521933. The next prime is 125521987. The reversal of 125521961 is 169125521.

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 125521961 - 2¹⁰ = 125520937 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (125571961) 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, 3303191 + ... + 3303228.

It is an arithmetic number, because the mean of its divisors is an integer number (33032100).

Almost surely, 2^125521961 is an apocalyptic number.

It is an amenable number.

125521961 is a deficient number, since it is larger than the sum of its proper divisors (6606439).

125521961 is an equidigital number, since it uses as much as digits as its factorization.

125521961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6606438.

The product of its digits is 5400, while the sum is 32.

The square root of 125521961 is about 11203.6583757271. The cubic root of 125521961 is about 500.6949815537.

The spelling of 125521961 in words is "one hundred twenty-five million, five hundred twenty-one thousand, nine hundred sixty-one".