61165640 has 64 divisors (see below), whose sum is σ = 144676800. Its totient is φ = 23240448.

The previous prime is 61165633. The next prime is 61165661. The reversal of 61165640 is 4656116.

It is a Harshad number since it is a multiple of its sum of digits (29).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 77327 + ... + 78113.

It is an arithmetic number, because the mean of its divisors is an integer number (2260575).

Almost surely, 2^61165640 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 61165640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (72338400).

61165640 is an abundant number, since it is smaller than the sum of its proper divisors (83511160).

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

61165640 is a wasteful number, since it uses less digits than its factorization.

61165640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 894 (or 890 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 29.

The square root of 61165640 is about 7820.8465014984. The cubic root of 61165640 is about 394.0057030619.

The spelling of 61165640 in words is "sixty-one million, one hundred sixty-five thousand, six hundred forty".