63491993 has 2 divisors, whose sum is σ = 63491994. Its totient is φ = 63491992.

The previous prime is 63491941. The next prime is 63492007. The reversal of 63491993 is 39919436.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 62932489 + 559504 = 7933^2 + 748^2 .

It is a cyclic number.

It is not a de Polignac number, because 63491993 - 2²⁴ = 46714777 is a prime.

It is a super-2 number, since 2×63491993² = 8062466350224098, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (63491893) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 31745996 + 31745997.

It is an arithmetic number, because the mean of its divisors is an integer number (31745997).

Almost surely, 2^63491993 is an apocalyptic number.

It is an amenable number.

63491993 is a deficient number, since it is larger than the sum of its proper divisors (1).

63491993 is an equidigital number, since it uses as much as digits as its factorization.

63491993 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 157464, while the sum is 44.

The square root of 63491993 is about 7968.1863055529. The cubic root of 63491993 is about 398.9388394183.

The spelling of 63491993 in words is "sixty-three million, four hundred ninety-one thousand, nine hundred ninety-three".