61781290 has 8 divisors (see below), whose sum is σ = 111206340. Its totient is φ = 24712512.

The previous prime is 61781267. The next prime is 61781297. The reversal of 61781290 is 9218716.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 61732449 + 48841 = 7857^2 + 221^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (61781297) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3089055 + ... + 3089074.

Almost surely, 2^61781290 is an apocalyptic number.

61781290 is a deficient number, since it is larger than the sum of its proper divisors (49425050).

61781290 is a wasteful number, since it uses less digits than its factorization.

61781290 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6178136.

The product of its (nonzero) digits is 6048, while the sum is 34.

The square root of 61781290 is about 7860.1075056261. The cubic root of 61781290 is about 395.3232199283.

The spelling of 61781290 in words is "sixty-one million, seven hundred eighty-one thousand, two hundred ninety".