81464525139 has 8 divisors (see below), whose sum is σ = 108621974160. Its totient is φ = 54308379776.

The previous prime is 81464525119. The next prime is 81464525201. The reversal of 81464525139 is 93152546418.

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

It is a cyclic number.

It is not a de Polignac number, because 81464525139 - 2⁹ = 81464524627 is a prime.

It is a super-2 number, since 2×81464525139² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (81464525119) 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, 169362 + ... + 437735.

It is an arithmetic number, because the mean of its divisors is an integer number (13577746770).

Almost surely, 2^81464525139 is an apocalyptic number.

81464525139 is a deficient number, since it is larger than the sum of its proper divisors (27157449021).

81464525139 is a wasteful number, since it uses less digits than its factorization.

81464525139 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 651829.

The product of its digits is 1036800, while the sum is 48.

The spelling of 81464525139 in words is "eighty-one billion, four hundred sixty-four million, five hundred twenty-five thousand, one hundred thirty-nine".