61404320625640 has 128 divisors (see below), whose sum is σ = 144953584680960. Its totient is φ = 23365883337984.

The previous prime is 61404320625611. The next prime is 61404320625647. The reversal of 61404320625640 is 4652602340416.

It is not an unprimeable number, because it can be changed into a prime (61404320625647) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 146660677 + ... + 147078763.

It is an arithmetic number, because the mean of its divisors is an integer number (1132449880320).

Almost surely, 2^{61404320625640} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 61404320625640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (72476792340480).

61404320625640 is an abundant number, since it is smaller than the sum of its proper divisors (83549264055320).

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

61404320625640 is a wasteful number, since it uses less digits than its factorization.

61404320625640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 418991 (or 418987 counting only the distinct ones).

The product of its (nonzero) digits is 829440, while the sum is 43.

The spelling of 61404320625640 in words is "sixty-one trillion, four hundred four billion, three hundred twenty million, six hundred twenty-five thousand, six hundred forty".