61821904 has 20 divisors (see below), whose sum is σ = 120010176. Its totient is φ = 30851552.

The previous prime is 61821889. The next prime is 61821923. The reversal of 61821904 is 40912816.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5577 + ... + 12439.

Almost surely, 2^61821904 is an apocalyptic number.

It is an amenable number.

61821904 is a deficient number, since it is larger than the sum of its proper divisors (58188272).

61821904 is a wasteful number, since it uses less digits than its factorization.

61821904 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7434 (or 7428 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 31.

The square root of 61821904 is about 7862.6906336190. The cubic root of 61821904 is about 395.4098272723.

It can be divided in two parts, 618 and 21904, that added together give a palindrome (22522).

The spelling of 61821904 in words is "sixty-one million, eight hundred twenty-one thousand, nine hundred four".