81270253 has 4 divisors (see below), whose sum is σ = 82803708. Its totient is φ = 79736800.

The previous prime is 81270229. The next prime is 81270257. The reversal of 81270253 is 35207218.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 27071209 + 54199044 = 5203^2 + 7362^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81270253 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81270257) 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, 766648 + ... + 766753.

It is an arithmetic number, because the mean of its divisors is an integer number (20700927).

Almost surely, 2^81270253 is an apocalyptic number.

It is an amenable number.

81270253 is a deficient number, since it is larger than the sum of its proper divisors (1533455).

81270253 is a wasteful number, since it uses less digits than its factorization.

81270253 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1533454.

The product of its (nonzero) digits is 3360, while the sum is 28.

The square root of 81270253 is about 9015.0015529671. The cubic root of 81270253 is about 433.1555372511.

Subtracting from 81270253 its sum of digits (28), we obtain a square (81270225 = 9015²).

The spelling of 81270253 in words is "eighty-one million, two hundred seventy thousand, two hundred fifty-three".