81274553 has 4 divisors (see below), whose sum is σ = 81598608. Its totient is φ = 80950500.

The previous prime is 81274549. The next prime is 81274561. The reversal of 81274553 is 35547218.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 81274553 - 2² = 81274549 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81274573) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 161651 + ... + 162152.

It is an arithmetic number, because the mean of its divisors is an integer number (20399652).

Almost surely, 2^81274553 is an apocalyptic number.

It is an amenable number.

81274553 is a deficient number, since it is larger than the sum of its proper divisors (324055).

81274553 is a wasteful number, since it uses less digits than its factorization.

81274553 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 324054.

The product of its digits is 33600, while the sum is 35.

The square root of 81274553 is about 9015.2400411747. The cubic root of 81274553 is about 433.1631765201.

The spelling of 81274553 in words is "eighty-one million, two hundred seventy-four thousand, five hundred fifty-three".