81629890579 has 2 divisors, whose sum is σ = 81629890580. Its totient is φ = 81629890578.

The previous prime is 81629890543. The next prime is 81629890609. The reversal of 81629890579 is 97509892618.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 81629890579 - 2¹³ = 81629882387 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 81629890579.

It is not a weakly prime, because it can be changed into another prime (81629890679) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40814945289 + 40814945290.

It is an arithmetic number, because the mean of its divisors is an integer number (40814945290).

Almost surely, 2^81629890579 is an apocalyptic number.

81629890579 is a deficient number, since it is larger than the sum of its proper divisors (1).

81629890579 is an equidigital number, since it uses as much as digits as its factorization.

81629890579 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 19595520, while the sum is 64.

The spelling of 81629890579 in words is "eighty-one billion, six hundred twenty-nine million, eight hundred ninety thousand, five hundred seventy-nine".