721225986491 has 2 divisors, whose sum is σ = 721225986492. Its totient is φ = 721225986490.

The previous prime is 721225986461. The next prime is 721225986541. The reversal of 721225986491 is 194689522127.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 721225986491 - 2⁶ = 721225986427 is a prime.

It is a super-2 number, since 2×721225986491² (a number of 25 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (721225986461) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 360612993245 + 360612993246.

It is an arithmetic number, because the mean of its divisors is an integer number (360612993246).

Almost surely, 2^721225986491 is an apocalyptic number.

721225986491 is a deficient number, since it is larger than the sum of its proper divisors (1).

721225986491 is an equidigital number, since it uses as much as digits as its factorization.

721225986491 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4354560, while the sum is 56.

The spelling of 721225986491 in words is "seven hundred twenty-one billion, two hundred twenty-five million, nine hundred eighty-six thousand, four hundred ninety-one".