51613635640 has 64 divisors (see below), whose sum is σ = 134400844800. Its totient is φ = 17472094848.

The previous prime is 51613635589. The next prime is 51613635643. The reversal of 51613635640 is 4653631615.

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a junction number, because it is equal to n+sod(n) for n = 51613635593 and 51613635602.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51613635643) 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 15 ways as a sum of consecutive naturals, for example, 1144554 + ... + 1188793.

It is an arithmetic number, because the mean of its divisors is an integer number (2100013200).

Almost surely, 2^51613635640 is an apocalyptic number.

It is an amenable number.

51613635640 is an abundant number, since it is smaller than the sum of its proper divisors (82787209160).

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

51613635640 is a wasteful number, since it uses less digits than its factorization.

51613635640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2333444 (or 2333440 counting only the distinct ones).

The product of its (nonzero) digits is 194400, while the sum is 40.

The spelling of 51613635640 in words is "fifty-one billion, six hundred thirteen million, six hundred thirty-five thousand, six hundred forty".