1997855051 has 2 divisors, whose sum is σ = 1997855052. Its totient is φ = 1997855050.

The previous prime is 1997855039. The next prime is 1997855059. The reversal of 1997855051 is 1505587991.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1997855051 - 2²⁶ = 1930746187 is a prime.

It is not a weakly prime, because it can be changed into another prime (1997855059) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 998927525 + 998927526.

It is an arithmetic number, because the mean of its divisors is an integer number (998927526).

Almost surely, 2^1997855051 is an apocalyptic number.

1997855051 is a deficient number, since it is larger than the sum of its proper divisors (1).

1997855051 is an equidigital number, since it uses as much as digits as its factorization.

1997855051 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 567000, while the sum is 50.

The square root of 1997855051 is about 44697.3718578621. The cubic root of 1997855051 is about 1259.4704777147.

The spelling of 1997855051 in words is "one billion, nine hundred ninety-seven million, eight hundred fifty-five thousand, fifty-one".