125215666 has 4 divisors (see below), whose sum is σ = 187823502. Its totient is φ = 62607832.

The previous prime is 125215663. The next prime is 125215667. The reversal of 125215666 is 666512521.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 666512521 = 6481 ⋅102841.

It can be written as a sum of positive squares in only one way, i.e., 99500625 + 25715041 = 9975^2 + 5071^2 .

It is not an unprimeable number, because it can be changed into a prime (125215663) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 31303915 + ... + 31303918.

Almost surely, 2^125215666 is an apocalyptic number.

125215666 is a deficient number, since it is larger than the sum of its proper divisors (62607836).

125215666 is an equidigital number, since it uses as much as digits as its factorization.

125215666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 62607835.

The product of its digits is 21600, while the sum is 34.

The square root of 125215666 is about 11189.9806076686. The cubic root of 125215666 is about 500.2873894496.

The spelling of 125215666 in words is "one hundred twenty-five million, two hundred fifteen thousand, six hundred sixty-six".