61643240 has 32 divisors (see below), whose sum is σ = 141319080. Its totient is φ = 24191232.

The previous prime is 61643191. The next prime is 61643297. The reversal of 61643240 is 4234616.

It can be written as a sum of positive squares in 4 ways, for example, as 59505796 + 2137444 = 7714^2 + 1462^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12419 + ... + 16658.

Almost surely, 2^61643240 is an apocalyptic number.

It is an amenable number.

61643240 is an abundant number, since it is smaller than the sum of its proper divisors (79675840).

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

61643240 is a wasteful number, since it uses less digits than its factorization.

61643240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29141 (or 29137 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 26.

The square root of 61643240 is about 7851.3209079747. The cubic root of 61643240 is about 395.0285510527.

Adding to 61643240 its reverse (4234616), we get a palindrome (65877856).

The spelling of 61643240 in words is "sixty-one million, six hundred forty-three thousand, two hundred forty".