63385781 has 4 divisors (see below), whose sum is σ = 63403200. Its totient is φ = 63368364.

The previous prime is 63385759. The next prime is 63385787. The reversal of 63385781 is 18758336.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 63385781 - 2¹⁸ = 63123637 is a prime.

It is a super-2 number, since 2×63385781² = 8035514465959922, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (63385787) 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, 941 + ... + 11298.

It is an arithmetic number, because the mean of its divisors is an integer number (15850800).

Almost surely, 2^63385781 is an apocalyptic number.

It is an amenable number.

63385781 is a deficient number, since it is larger than the sum of its proper divisors (17419).

63385781 is a wasteful number, since it uses less digits than its factorization.

63385781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17418.

The product of its digits is 120960, while the sum is 41.

The square root of 63385781 is about 7961.5187621458. The cubic root of 63385781 is about 398.7162615296.

The spelling of 63385781 in words is "sixty-three million, three hundred eighty-five thousand, seven hundred eighty-one".