61637781040 has 40 divisors (see below), whose sum is σ = 156335828688. Its totient is φ = 22413738240.

The previous prime is 61637781011. The next prime is 61637781119. The reversal of 61637781040 is 4018773616.

It is a tau number, because it is divible by the number of its divisors (40).

It is a Smith number, since the sum of its digits (43) coincides with the sum of the digits of its prime factors.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 35020587 + ... + 35022346.

Almost surely, 2^61637781040 is an apocalyptic number.

It is an amenable number.

61637781040 is an abundant number, since it is smaller than the sum of its proper divisors (94698047648).

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

61637781040 is a wasteful number, since it uses less digits than its factorization.

61637781040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 70042957 (or 70042951 counting only the distinct ones).

The product of its (nonzero) digits is 169344, while the sum is 43.

The spelling of 61637781040 in words is "sixty-one billion, six hundred thirty-seven million, seven hundred eighty-one thousand, forty".