1661412461 has 2 divisors, whose sum is σ = 1661412462. Its totient is φ = 1661412460.

The previous prime is 1661412449. The next prime is 1661412527. The reversal of 1661412461 is 1642141661.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1616442025 + 44970436 = 40205^2 + 6706^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1661412461 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1661411461) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 830706230 + 830706231.

It is an arithmetic number, because the mean of its divisors is an integer number (830706231).

Almost surely, 2^1661412461 is an apocalyptic number.

It is an amenable number.

1661412461 is a deficient number, since it is larger than the sum of its proper divisors (1).

1661412461 is an equidigital number, since it uses as much as digits as its factorization.

1661412461 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6912, while the sum is 32.

The square root of 1661412461 is about 40760.4276351463. The cubic root of 1661412461 is about 1184.3838800150.

The spelling of 1661412461 in words is "one billion, six hundred sixty-one million, four hundred twelve thousand, four hundred sixty-one".