61643812 has 6 divisors (see below), whose sum is σ = 107876678. Its totient is φ = 30821904.

The previous prime is 61643797. The next prime is 61643831. The reversal of 61643812 is 21834616.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 59351616 + 2292196 = 7704^2 + 1514^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7705473 + ... + 7705480.

Almost surely, 2^61643812 is an apocalyptic number.

It is an amenable number.

61643812 is a deficient number, since it is larger than the sum of its proper divisors (46232866).

61643812 is a wasteful number, since it uses less digits than its factorization.

61643812 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15410957 (or 15410955 counting only the distinct ones).

The product of its digits is 6912, while the sum is 31.

The square root of 61643812 is about 7851.3573348817. The cubic root of 61643812 is about 395.0297728987.

The spelling of 61643812 in words is "sixty-one million, six hundred forty-three thousand, eight hundred twelve".