61641554443 has 12 divisors (see below), whose sum is σ = 71709741480. Its totient is φ = 52832479392.

The previous prime is 61641554419. The next prime is 61641554459. The reversal of 61641554443 is 34445514616.

It is a de Polignac number, because none of the positive numbers 2^k-61641554443 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 61641554443.

It is not an unprimeable number, because it can be changed into a prime (61641504443) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1230280 + ... + 1279402.

It is an arithmetic number, because the mean of its divisors is an integer number (5975811790).

Almost surely, 2^61641554443 is an apocalyptic number.

61641554443 is a deficient number, since it is larger than the sum of its proper divisors (10068187037).

61641554443 is a wasteful number, since it uses less digits than its factorization.

61641554443 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 74746 (or 74739 counting only the distinct ones).

The product of its digits is 691200, while the sum is 43.

The spelling of 61641554443 in words is "sixty-one billion, six hundred forty-one million, five hundred fifty-four thousand, four hundred forty-three".