81255601 has 4 divisors (see below), whose sum is σ = 92863552. Its totient is φ = 69647652.

The previous prime is 81255583. The next prime is 81255637. The reversal of 81255601 is 10655218.

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 81255601 - 2¹³ = 81247409 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 81255601.

It is not an unprimeable number, because it can be changed into a prime (81255641) 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, 5803965 + ... + 5803978.

It is an arithmetic number, because the mean of its divisors is an integer number (23215888).

Almost surely, 2^81255601 is an apocalyptic number.

It is an amenable number.

81255601 is a deficient number, since it is larger than the sum of its proper divisors (11607951).

81255601 is a wasteful number, since it uses less digits than its factorization.

81255601 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11607950.

The product of its (nonzero) digits is 2400, while the sum is 28.

The square root of 81255601 is about 9014.1888708857. The cubic root of 81255601 is about 433.1295048628.

The spelling of 81255601 in words is "eighty-one million, two hundred fifty-five thousand, six hundred one".