991000010051 has 2 divisors, whose sum is σ = 991000010052. Its totient is φ = 991000010050.

The previous prime is 991000010027. The next prime is 991000010083. The reversal of 991000010051 is 150010000199.

It is a happy number.

991000010051 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is an emirp because it is prime and its reverse (150010000199) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 991000010051 - 2²⁶ = 990932901187 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 991000010051.

It is not a weakly prime, because it can be changed into another prime (991000610051) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 495500005025 + 495500005026.

It is an arithmetic number, because the mean of its divisors is an integer number (495500005026).

Almost surely, 2^991000010051 is an apocalyptic number.

991000010051 is a deficient number, since it is larger than the sum of its proper divisors (1).

991000010051 is an equidigital number, since it uses as much as digits as its factorization.

991000010051 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 405, while the sum is 26.

The spelling of 991000010051 in words is "nine hundred ninety-one billion, ten thousand, fifty-one".