125421515 has 4 divisors (see below), whose sum is σ = 150505824. Its totient is φ = 100337208.

The previous prime is 125421511. The next prime is 125421523. The reversal of 125421515 is 515124521.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 515124521 = 137 ⋅3760033.

It is a cyclic number.

It is not a de Polignac number, because 125421515 - 2² = 125421511 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (125421511) 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, 12542147 + ... + 12542156.

It is an arithmetic number, because the mean of its divisors is an integer number (37626456).

Almost surely, 2^125421515 is an apocalyptic number.

125421515 is a deficient number, since it is larger than the sum of its proper divisors (25084309).

125421515 is an equidigital number, since it uses as much as digits as its factorization.

125421515 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25084308.

The product of its digits is 2000, while the sum is 26.

The square root of 125421515 is about 11199.1747463820. The cubic root of 125421515 is about 500.5613894479.

The spelling of 125421515 in words is "one hundred twenty-five million, four hundred twenty-one thousand, five hundred fifteen".