1864917521 has 2 divisors, whose sum is σ = 1864917522. Its totient is φ = 1864917520.

The previous prime is 1864917479. The next prime is 1864917563. The reversal of 1864917521 is 1257194681.

It is a balanced prime because it is at equal distance from previous prime (1864917479) and next prime (1864917563).

It can be written as a sum of positive squares in only one way, i.e., 1470339025 + 394578496 = 38345^2 + 19864^2 .

It is a cyclic number.

It is not a de Polignac number, because 1864917521 - 2²² = 1860723217 is a prime.

It is not a weakly prime, because it can be changed into another prime (1864917581) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 932458760 + 932458761.

It is an arithmetic number, because the mean of its divisors is an integer number (932458761).

Almost surely, 2^1864917521 is an apocalyptic number.

It is an amenable number.

1864917521 is a deficient number, since it is larger than the sum of its proper divisors (1).

1864917521 is an equidigital number, since it uses as much as digits as its factorization.

1864917521 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 120960, while the sum is 44.

The square root of 1864917521 is about 43184.6908174645. The cubic root of 1864917521 is about 1230.8917940481.

The spelling of 1864917521 in words is "one billion, eight hundred sixty-four million, nine hundred seventeen thousand, five hundred twenty-one".