1661763457 has 2 divisors, whose sum is σ = 1661763458. Its totient is φ = 1661763456.

The previous prime is 1661763419. The next prime is 1661763479. The reversal of 1661763457 is 7543671661.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1474867216 + 186896241 = 38404^2 + 13671^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1661763457 is a prime.

It is a super-2 number, since 2×1661763457² = 5522915574041181698, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1661763157) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 830881728 + 830881729.

It is an arithmetic number, because the mean of its divisors is an integer number (830881729).

Almost surely, 2^1661763457 is an apocalyptic number.

It is an amenable number.

1661763457 is a deficient number, since it is larger than the sum of its proper divisors (1).

1661763457 is an equidigital number, since it uses as much as digits as its factorization.

1661763457 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 635040, while the sum is 46.

The square root of 1661763457 is about 40764.7330053810. The cubic root of 1661763457 is about 1184.4672798816.

The spelling of 1661763457 in words is "one billion, six hundred sixty-one million, seven hundred sixty-three thousand, four hundred fifty-seven".