81603757399 has 2 divisors, whose sum is σ = 81603757400. Its totient is φ = 81603757398.

The previous prime is 81603757363. The next prime is 81603757429. The reversal of 81603757399 is 99375730618.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 81603757399 - 2²³ = 81595368791 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81603757199) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40801878699 + 40801878700.

It is an arithmetic number, because the mean of its divisors is an integer number (40801878700).

Almost surely, 2^81603757399 is an apocalyptic number.

81603757399 is a deficient number, since it is larger than the sum of its proper divisors (1).

81603757399 is an equidigital number, since it uses as much as digits as its factorization.

81603757399 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8573040, while the sum is 58.

The spelling of 81603757399 in words is "eighty-one billion, six hundred three million, seven hundred fifty-seven thousand, three hundred ninety-nine".