61683921 has 24 divisors (see below), whose sum is σ = 98553000. Its totient is φ = 36930816.

The previous prime is 61683917. The next prime is 61683929. The reversal of 61683921 is 12938616.

61683921 is a `hidden beast` number, since 616 + 8 + 39 + 2 + 1 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 16646400 + 45037521 = 4080^2 + 6711^2 .

It is not a de Polignac number, because 61683921 - 2² = 61683917 is a prime.

It is a super-2 number, since 2×61683921² = 7609812219868482, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61683929) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2796 + ... + 11453.

It is an arithmetic number, because the mean of its divisors is an integer number (4106375).

Almost surely, 2^61683921 is an apocalyptic number.

It is an amenable number.

61683921 is a deficient number, since it is larger than the sum of its proper divisors (36869079).

61683921 is a wasteful number, since it uses less digits than its factorization.

61683921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14305 (or 14302 counting only the distinct ones).

The product of its digits is 15552, while the sum is 36.

The square root of 61683921 is about 7853.9111912473. The cubic root of 61683921 is about 395.1154306665.

The spelling of 61683921 in words is "sixty-one million, six hundred eighty-three thousand, nine hundred twenty-one".