61509994 has 24 divisors (see below), whose sum is σ = 115587108. Its totient is φ = 24333120.

The previous prime is 61509991. The next prime is 61510039. The reversal of 61509994 is 49990516.

61509994 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 58323769 + 3186225 = 7637^2 + 1785^2 .

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 a self number, because there is not a number n which added to its sum of digits gives 61509994.

It is not an unprimeable number, because it can be changed into a prime (61509991) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 22867 + ... + 25414.

Almost surely, 2^61509994 is an apocalyptic number.

61509994 is a deficient number, since it is larger than the sum of its proper divisors (54077114).

61509994 is a wasteful number, since it uses less digits than its factorization.

61509994 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 48310 (or 48303 counting only the distinct ones).

The product of its (nonzero) digits is 87480, while the sum is 43.

The square root of 61509994 is about 7842.8307389615. The cubic root of 61509994 is about 394.7437188185.

The spelling of 61509994 in words is "sixty-one million, five hundred nine thousand, nine hundred ninety-four".