761991421 has 2 divisors, whose sum is σ = 761991422. Its totient is φ = 761991420.

The previous prime is 761991413. The next prime is 761991479. The reversal of 761991421 is 124199167.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 642876025 + 119115396 = 25355^2 + 10914^2 .

It is a cyclic number.

It is not a de Polignac number, because 761991421 - 2³ = 761991413 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (761991481) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 380995710 + 380995711.

It is an arithmetic number, because the mean of its divisors is an integer number (380995711).

Almost surely, 2^761991421 is an apocalyptic number.

It is an amenable number.

761991421 is a deficient number, since it is larger than the sum of its proper divisors (1).

761991421 is an equidigital number, since it uses as much as digits as its factorization.

761991421 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 27216, while the sum is 40.

The square root of 761991421 is about 27604.1920910575. The cubic root of 761991421 is about 913.3769073492.

The spelling of 761991421 in words is "seven hundred sixty-one million, nine hundred ninety-one thousand, four hundred twenty-one".