2515625721 has 32 divisors (see below), whose sum is σ = 4277011200. Its totient is φ = 1431509760.

The previous prime is 2515625719. The next prime is 2515625729. The reversal of 2515625721 is 1275265152.

2515625721 is a `hidden beast` number, since 2 + 5 + 1 + 5 + 625 + 7 + 21 = 666.

It is not a de Polignac number, because 2515625721 - 2¹ = 2515625719 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (2515625729) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 17935 + ... + 73163.

It is an arithmetic number, because the mean of its divisors is an integer number (133656600).

Almost surely, 2^2515625721 is an apocalyptic number.

2515625721 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

2515625721 is a deficient number, since it is larger than the sum of its proper divisors (1761385479).

2515625721 is a wasteful number, since it uses less digits than its factorization.

2515625721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 55486 (or 55480 counting only the distinct ones).

The product of its digits is 42000, while the sum is 36.

The square root of 2515625721 is about 50156.0138069205. The cubic root of 2515625721 is about 1360.0305862859.

The spelling of 2515625721 in words is "two billion, five hundred fifteen million, six hundred twenty-five thousand, seven hundred twenty-one".