61277440 has 108 divisors (see below), whose sum is σ = 170917236. Its totient is φ = 20987904.

The previous prime is 61277431. The next prime is 61277443. The reversal of 61277440 is 4477216.

It can be written as a sum of positive squares in 2 ways, for example, as 42198016 + 19079424 = 6496^2 + 4368^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61277443) 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, 62232 + ... + 63208.

It is an arithmetic number, because the mean of its divisors is an integer number (1582567).

Almost surely, 2^61277440 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 61277440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (85458618).

61277440 is an abundant number, since it is smaller than the sum of its proper divisors (109639796).

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

61277440 is an equidigital number, since it uses as much as digits as its factorization.

61277440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1012 (or 991 counting only the distinct ones).

The product of its (nonzero) digits is 9408, while the sum is 31.

The square root of 61277440 is about 7827.9908022429. The cubic root of 61277440 is about 394.2456145895.

The spelling of 61277440 in words is "sixty-one million, two hundred seventy-seven thousand, four hundred forty".