1901998837 has 2 divisors, whose sum is σ = 1901998838. Its totient is φ = 1901998836.

The previous prime is 1901998783. The next prime is 1901998853. The reversal of 1901998837 is 7388991091.

Together with previous prime (1901998783) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1270280881 + 631717956 = 35641^2 + 25134^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1901998837 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1901993837) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 950999418 + 950999419.

It is an arithmetic number, because the mean of its divisors is an integer number (950999419).

Almost surely, 2^1901998837 is an apocalyptic number.

It is an amenable number.

1901998837 is a deficient number, since it is larger than the sum of its proper divisors (1).

1901998837 is an equidigital number, since it uses as much as digits as its factorization.

1901998837 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 979776, while the sum is 55.

The square root of 1901998837 is about 43611.9116412019. The cubic root of 1901998837 is about 1238.9965079744.

The spelling of 1901998837 in words is "one billion, nine hundred one million, nine hundred ninety-eight thousand, eight hundred thirty-seven".