85781623225 has 27 divisors (see below), whose sum is σ = 112298669103. Its totient is φ = 64992353040.

The previous prime is 85781623199. The next prime is 85781623243. The reversal of 85781623225 is 52232618758.

The square root of 85781623225 is 292885.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 30881384361 + 54900238864 = 175731^2 + 234308^2 .

It is not a de Polignac number, because 85781623225 - 2⁹ = 85781622713 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 27822534 + ... + 27825616.

Almost surely, 2^85781623225 is an apocalyptic number.

85781623225 is the 292885-th square number.

85781623225 is the 146443-rd centered octagonal number.

It is an amenable number.

85781623225 is a deficient number, since it is larger than the sum of its proper divisors (26517045878).

85781623225 is an frugal number, since it uses more digits than its factorization.

85781623225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6214 (or 3107 counting only the distinct ones).

The product of its digits is 1612800, while the sum is 49.

Multiplying 85781623225 by its sum of digits (49), we get a square (4203299538025 = 2050195²).

The spelling of 85781623225 in words is "eighty-five billion, seven hundred eighty-one million, six hundred twenty-three thousand, two hundred twenty-five".