63551861 has 2 divisors, whose sum is σ = 63551862. Its totient is φ = 63551860.

The previous prime is 63551821. The next prime is 63551863. The reversal of 63551861 is 16815536.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 41036836 + 22515025 = 6406^2 + 4745^2 .

It is a cyclic number.

It is not a de Polignac number, because 63551861 - 2¹⁸ = 63289717 is a prime.

Together with 63551863, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (63551863) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 31775930 + 31775931.

It is an arithmetic number, because the mean of its divisors is an integer number (31775931).

Almost surely, 2^63551861 is an apocalyptic number.

It is an amenable number.

63551861 is a deficient number, since it is larger than the sum of its proper divisors (1).

63551861 is an equidigital number, since it uses as much as digits as its factorization.

63551861 is an evil number, because the sum of its binary digits is even.

The product of its digits is 21600, while the sum is 35.

The square root of 63551861 is about 7971.9421096744. The cubic root of 63551861 is about 399.0641894372.

The spelling of 63551861 in words is "sixty-three million, five hundred fifty-one thousand, eight hundred sixty-one".