1024991861 has 2 divisors, whose sum is σ = 1024991862. Its totient is φ = 1024991860.

The previous prime is 1024991833. The next prime is 1024991881. The reversal of 1024991861 is 1681994201.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 725494225 + 299497636 = 26935^2 + 17306^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1024991861 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1024991881) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 512495930 + 512495931.

It is an arithmetic number, because the mean of its divisors is an integer number (512495931).

Almost surely, 2^1024991861 is an apocalyptic number.

It is an amenable number.

1024991861 is a deficient number, since it is larger than the sum of its proper divisors (1).

1024991861 is an equidigital number, since it uses as much as digits as its factorization.

1024991861 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 31104, while the sum is 41.

The square root of 1024991861 is about 32015.4940770871. The cubic root of 1024991861 is about 1008.2621688971.

The spelling of 1024991861 in words is "one billion, twenty-four million, nine hundred ninety-one thousand, eight hundred sixty-one".