761571721 has 2 divisors, whose sum is σ = 761571722. Its totient is φ = 761571720.

The previous prime is 761571719. The next prime is 761571829. The reversal of 761571721 is 127175167.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 446899600 + 314672121 = 21140^2 + 17739^2 .

It is a cyclic number.

It is not a de Polignac number, because 761571721 - 2¹ = 761571719 is a prime.

Together with 761571719, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (761541721) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 380785860 + 380785861.

It is an arithmetic number, because the mean of its divisors is an integer number (380785861).

Almost surely, 2^761571721 is an apocalyptic number.

It is an amenable number.

761571721 is a deficient number, since it is larger than the sum of its proper divisors (1).

761571721 is an equidigital number, since it uses as much as digits as its factorization.

761571721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 20580, while the sum is 37.

The square root of 761571721 is about 27596.5889377655. The cubic root of 761571721 is about 913.2091824990.

The spelling of 761571721 in words is "seven hundred sixty-one million, five hundred seventy-one thousand, seven hundred twenty-one".