1851994537 has 2 divisors, whose sum is σ = 1851994538. Its totient is φ = 1851994536.

The previous prime is 1851994531. The next prime is 1851994541. The reversal of 1851994537 is 7354991581.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1646817561 + 205176976 = 40581^2 + 14324^2 .

It is a cyclic number.

It is not a de Polignac number, because 1851994537 - 2⁷ = 1851994409 is a prime.

It is not a weakly prime, because it can be changed into another prime (1851994531) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 925997268 + 925997269.

It is an arithmetic number, because the mean of its divisors is an integer number (925997269).

Almost surely, 2^1851994537 is an apocalyptic number.

It is an amenable number.

1851994537 is a deficient number, since it is larger than the sum of its proper divisors (1).

1851994537 is an equidigital number, since it uses as much as digits as its factorization.

1851994537 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1360800, while the sum is 52.

The square root of 1851994537 is about 43034.8061108680. The cubic root of 1851994537 is about 1228.0420381316.

The spelling of 1851994537 in words is "one billion, eight hundred fifty-one million, nine hundred ninety-four thousand, five hundred thirty-seven".