63890781 has 8 divisors (see below), whose sum is σ = 85236480. Its totient is φ = 42569472.

The previous prime is 63890747. The next prime is 63890821. The reversal of 63890781 is 18709836.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 63890781 - 2⁷ = 63890653 is a prime.

It is a super-2 number, since 2×63890781² = 8164063793579922, which contains 22 as substring.

It is an alternating number because its digits alternate between even and odd.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (63890581) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1300 + ... + 11378.

It is an arithmetic number, because the mean of its divisors is an integer number (10654560).

Almost surely, 2^63890781 is an apocalyptic number.

It is an amenable number.

63890781 is a deficient number, since it is larger than the sum of its proper divisors (21345699).

63890781 is a wasteful number, since it uses less digits than its factorization.

63890781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12195.

The product of its (nonzero) digits is 72576, while the sum is 42.

The square root of 63890781 is about 7993.1708977101. The cubic root of 63890781 is about 399.7723308582.

It can be divided in two parts, 638 and 90781, that added together give a palindrome (91419).

The spelling of 63890781 in words is "sixty-three million, eight hundred ninety thousand, seven hundred eighty-one".