1809961357 has 2 divisors, whose sum is σ = 1809961358. Its totient is φ = 1809961356.

The previous prime is 1809961297. The next prime is 1809961411. The reversal of 1809961357 is 7531699081.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1809736681 + 224676 = 42541^2 + 474^2 .

It is a cyclic number.

It is not a de Polignac number, because 1809961357 - 2⁷ = 1809961229 is a prime.

It is a super-2 number, since 2×1809961357² = 6551920227666562898, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 1809961357.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1809961757) 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, 904980678 + 904980679.

It is an arithmetic number, because the mean of its divisors is an integer number (904980679).

Almost surely, 2^1809961357 is an apocalyptic number.

It is an amenable number.

1809961357 is a deficient number, since it is larger than the sum of its proper divisors (1).

1809961357 is an equidigital number, since it uses as much as digits as its factorization.

1809961357 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 408240, while the sum is 49.

The square root of 1809961357 is about 42543.6406176058. The cubic root of 1809961357 is about 1218.6802347897.

The spelling of 1809961357 in words is "one billion, eight hundred nine million, nine hundred sixty-one thousand, three hundred fifty-seven".