63866989 has 4 divisors (see below), whose sum is σ = 63944860. Its totient is φ = 63789120.

The previous prime is 63866987. The next prime is 63866993. The reversal of 63866989 is 98966836.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 45118089 + 18748900 = 6717^2 + 4330^2 .

It is a cyclic number.

It is not a de Polignac number, because 63866989 - 2¹ = 63866987 is a prime.

It is a super-2 number, since 2×63866989² = 8157984567852242, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (63866983) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 37692 + ... + 39349.

It is an arithmetic number, because the mean of its divisors is an integer number (15986215).

Almost surely, 2^63866989 is an apocalyptic number.

It is an amenable number.

63866989 is a deficient number, since it is larger than the sum of its proper divisors (77871).

63866989 is an equidigital number, since it uses as much as digits as its factorization.

63866989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 77870.

The product of its digits is 3359232, while the sum is 55.

The square root of 63866989 is about 7991.6824886878. The cubic root of 63866989 is about 399.7227015584.

The spelling of 63866989 in words is "sixty-three million, eight hundred sixty-six thousand, nine hundred eighty-nine".