125121520 has 80 divisors (see below), whose sum is σ = 300837888. Its totient is φ = 48369920.

The previous prime is 125121511. The next prime is 125121533. The reversal of 125121520 is 25121521.

It is a tau number, because it is divible by the number of its divisors (80).

It is a super-2 number, since 2×125121520² = 31310789534220800, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 402165 + ... + 402475.

Almost surely, 2^125121520 is an apocalyptic number.

125121520 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 125121520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (150418944).

125121520 is an abundant number, since it is smaller than the sum of its proper divisors (175716368).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

125121520 is a wasteful number, since it uses less digits than its factorization.

125121520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 478 (or 472 counting only the distinct ones).

The product of its (nonzero) digits is 200, while the sum is 19.

The square root of 125121520 is about 11185.7731069426. The cubic root of 125121520 is about 500.1619741897.

Subtracting from 125121520 its reverse (25121521), we obtain a palindrome (99999999).

The spelling of 125121520 in words is "one hundred twenty-five million, one hundred twenty-one thousand, five hundred twenty".