81207526399 has 16 divisors (see below), whose sum is σ = 84370320000. Its totient is φ = 78069277440.

The previous prime is 81207526373. The next prime is 81207526409. The reversal of 81207526399 is 99362570218.

It is a cyclic number.

It is not a de Polignac number, because 81207526399 - 2¹³ = 81207518207 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 (81207526319) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 23960397 + ... + 23963785.

It is an arithmetic number, because the mean of its divisors is an integer number (5273145000).

Almost surely, 2^81207526399 is an apocalyptic number.

81207526399 is a deficient number, since it is larger than the sum of its proper divisors (3162793601).

81207526399 is a wasteful number, since it uses less digits than its factorization.

81207526399 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6738.

The product of its (nonzero) digits is 1632960, while the sum is 52.

The spelling of 81207526399 in words is "eighty-one billion, two hundred seven million, five hundred twenty-six thousand, three hundred ninety-nine".