61805240 has 64 divisors (see below), whose sum is σ = 159667200. Its totient is φ = 21091968.

The previous prime is 61805239. The next prime is 61805243. The reversal of 61805240 is 4250816.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61805243) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 85601 + ... + 86319.

It is an arithmetic number, because the mean of its divisors is an integer number (2494800).

Almost surely, 2^61805240 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 61805240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (79833600).

61805240 is an abundant number, since it is smaller than the sum of its proper divisors (97861960).

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

61805240 is a wasteful number, since it uses less digits than its factorization.

61805240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1044 (or 1040 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 26.

The square root of 61805240 is about 7861.6308740617. The cubic root of 61805240 is about 395.3742967076.

The spelling of 61805240 in words is "sixty-one million, eight hundred five thousand, two hundred forty".