81907628801 has 2 divisors, whose sum is σ = 81907628802. Its totient is φ = 81907628800.

The previous prime is 81907628749. The next prime is 81907628807. The reversal of 81907628801 is 10882670918.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 72264192400 + 9643436401 = 268820^2 + 98201^2 .

It is a cyclic number.

It is not a de Polignac number, because 81907628801 - 2¹⁴ = 81907612417 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 81907628801.

It is not a weakly prime, because it can be changed into another prime (81907628807) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40953814400 + 40953814401.

It is an arithmetic number, because the mean of its divisors is an integer number (40953814401).

Almost surely, 2^81907628801 is an apocalyptic number.

It is an amenable number.

81907628801 is a deficient number, since it is larger than the sum of its proper divisors (1).

81907628801 is an equidigital number, since it uses as much as digits as its factorization.

81907628801 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 387072, while the sum is 50.

The spelling of 81907628801 in words is "eighty-one billion, nine hundred seven million, six hundred twenty-eight thousand, eight hundred one".