81373253 has 8 divisors (see below), whose sum is σ = 87741696. Its totient is φ = 75020400.

The previous prime is 81373247. The next prime is 81373261. The reversal of 81373253 is 35237318.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 81373253 - 2⁸ = 81372997 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 (81373223) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8408 + ... + 15278.

It is an arithmetic number, because the mean of its divisors is an integer number (10967712).

Almost surely, 2^81373253 is an apocalyptic number.

It is an amenable number.

81373253 is a deficient number, since it is larger than the sum of its proper divisors (6368443).

81373253 is a wasteful number, since it uses less digits than its factorization.

81373253 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7795.

The product of its digits is 15120, while the sum is 32.

The square root of 81373253 is about 9020.7124441476. The cubic root of 81373253 is about 433.3384503669.

The spelling of 81373253 in words is "eighty-one million, three hundred seventy-three thousand, two hundred fifty-three".