61201640 has 32 divisors (see below), whose sum is σ = 137997000. Its totient is φ = 24428544.

The previous prime is 61201631. The next prime is 61201669. The reversal of 61201640 is 4610216.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 21031396 + 40170244 = 4586^2 + 6338^2 .

It is a Harshad number since it is a multiple of its sum of digits (20).

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, 21416 + ... + 24104.

Almost surely, 2^61201640 is an apocalyptic number.

It is an amenable number.

61201640 is an abundant number, since it is smaller than the sum of its proper divisors (76795360).

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

61201640 is a wasteful number, since it uses less digits than its factorization.

61201640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3269 (or 3265 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 20.

The square root of 61201640 is about 7823.1477040894. The cubic root of 61201640 is about 394.0829873206.

Adding to 61201640 its reverse (4610216), we get a palindrome (65811856).

The spelling of 61201640 in words is "sixty-one million, two hundred one thousand, six hundred forty".