63809820 has 72 divisors (see below), whose sum is σ = 201985056. Its totient is φ = 16275072.

The previous prime is 63809813. The next prime is 63809861. The reversal of 63809820 is 2890836.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3567 + ... + 11846.

It is an arithmetic number, because the mean of its divisors is an integer number (2805348).

Almost surely, 2^63809820 is an apocalyptic number.

63809820 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

63809820 is an abundant number, since it is smaller than the sum of its proper divisors (138175236).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

63809820 is a wasteful number, since it uses less digits than its factorization.

63809820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15451 (or 15446 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 36.

The square root of 63809820 is about 7988.1049066722. The cubic root of 63809820 is about 399.6033985649.

The spelling of 63809820 in words is "sixty-three million, eight hundred nine thousand, eight hundred twenty".