81360973501 has 4 divisors (see below), whose sum is σ = 81368267904. Its totient is φ = 81353679100.

The previous prime is 81360973483. The next prime is 81360973517. The reversal of 81360973501 is 10537906318.

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, and also an emirpimes, since its reverse is a distinct semiprime: 10537906318 = 2 ⋅5268953159.

It is a cyclic number.

It is not a de Polignac number, because 81360973501 - 2²¹ = 81358876349 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 (81360973571) 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, 3630445 + ... + 3652786.

It is an arithmetic number, because the mean of its divisors is an integer number (20342066976).

Almost surely, 2^81360973501 is an apocalyptic number.

It is an amenable number.

81360973501 is a deficient number, since it is larger than the sum of its proper divisors (7294403).

81360973501 is a wasteful number, since it uses less digits than its factorization.

81360973501 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7294402.

The product of its (nonzero) digits is 136080, while the sum is 43.

The spelling of 81360973501 in words is "eighty-one billion, three hundred sixty million, nine hundred seventy-three thousand, five hundred one".