1901537681 has 2 divisors, whose sum is σ = 1901537682. Its totient is φ = 1901537680.

The previous prime is 1901537641. The next prime is 1901537683. The reversal of 1901537681 is 1867351091.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 953821456 + 947716225 = 30884^2 + 30785^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1901537681 is a prime.

It is a super-2 number, since 2×1901537681² = 7231691104525715522, which contains 22 as substring.

Together with 1901537683, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (1901537683) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 950768840 + 950768841.

It is an arithmetic number, because the mean of its divisors is an integer number (950768841).

Almost surely, 2^1901537681 is an apocalyptic number.

It is an amenable number.

1901537681 is a deficient number, since it is larger than the sum of its proper divisors (1).

1901537681 is an equidigital number, since it uses as much as digits as its factorization.

1901537681 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 45360, while the sum is 41.

The square root of 1901537681 is about 43606.6242788868. The cubic root of 1901537681 is about 1238.8963647555.

The spelling of 1901537681 in words is "one billion, nine hundred one million, five hundred thirty-seven thousand, six hundred eighty-one".