81367390045 has 4 divisors (see below), whose sum is σ = 97640868060. Its totient is φ = 65093912032.

The previous prime is 81367390021. The next prime is 81367390061. The reversal of 81367390045 is 54009376318.

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 11829172644 + 69538217401 = 108762^2 + 263701^2 .

It is a cyclic number.

It is not a de Polignac number, because 81367390045 - 2²⁵ = 81333835613 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 81367389977 and 81367390004.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8136739000 + ... + 8136739009.

It is an arithmetic number, because the mean of its divisors is an integer number (24410217015).

Almost surely, 2^81367390045 is an apocalyptic number.

It is an amenable number.

81367390045 is a deficient number, since it is larger than the sum of its proper divisors (16273478015).

81367390045 is a wasteful number, since it uses less digits than its factorization.

81367390045 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16273478014.

The product of its (nonzero) digits is 544320, while the sum is 46.

The spelling of 81367390045 in words is "eighty-one billion, three hundred sixty-seven million, three hundred ninety thousand, forty-five".