61811507940 has 384 divisors, whose sum is σ = 227595325440. Its totient is φ = 12169377792.

The previous prime is 61811507887. The next prime is 61811507981. The reversal of 61811507940 is 4970511816.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a junction number, because it is equal to n+sod(n) for n = 61811507892 and 61811507901.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 6946134 + ... + 6955026.

It is an arithmetic number, because the mean of its divisors is an integer number (592696160).

Almost surely, 2^61811507940 is an apocalyptic number.

61811507940 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 61811507940, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (113797662720).

61811507940 is an abundant number, since it is smaller than the sum of its proper divisors (165783817500).

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

61811507940 is a wasteful number, since it uses less digits than its factorization.

61811507940 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9011 (or 9009 counting only the distinct ones).

The product of its (nonzero) digits is 60480, while the sum is 42.

The spelling of 61811507940 in words is "sixty-one billion, eight hundred eleven million, five hundred seven thousand, nine hundred forty".