81250025 has 12 divisors (see below), whose sum is σ = 104225100. Its totient is φ = 62758080.

The previous prime is 81250019. The next prime is 81250027. The reversal of 81250025 is 52005218.

81250025 = T₂₅₃₇ + T₂₅₃₈ + ... + T₂₅₆₁.

It can be written as a sum of positive squares in 6 ways, for example, as 2111209 + 79138816 = 1453^2 + 8896^2 .

It is not a de Polignac number, because 81250025 - 2¹⁶ = 81184489 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81250027) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 55310 + ... + 56759.

It is an arithmetic number, because the mean of its divisors is an integer number (8685425).

Almost surely, 2^81250025 is an apocalyptic number.

It is an amenable number.

81250025 is a deficient number, since it is larger than the sum of its proper divisors (22975075).

81250025 is a wasteful number, since it uses less digits than its factorization.

81250025 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 112108 (or 112103 counting only the distinct ones).

The product of its (nonzero) digits is 800, while the sum is 23.

The square root of 81250025 is about 9013.8795754104. The cubic root of 81250025 is about 433.1195970930.

The spelling of 81250025 in words is "eighty-one million, two hundred fifty thousand, twenty-five".