61213666 has 8 divisors (see below), whose sum is σ = 92852460. Its totient is φ = 30262848.

The previous prime is 61213661. The next prime is 61213667. The reversal of 61213666 is 66631216.

61213666 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 59737441 + 1476225 = 7729^2 + 1215^2 .

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

It is a super-2 number, since 2×61213666² = 7494225810319112, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (61213661) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 171771 + ... + 172126.

Almost surely, 2^61213666 is an apocalyptic number.

61213666 is a deficient number, since it is larger than the sum of its proper divisors (31638794).

61213666 is a wasteful number, since it uses less digits than its factorization.

61213666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 343988.

The product of its digits is 7776, while the sum is 31.

The square root of 61213666 is about 7823.9162827832. The cubic root of 61213666 is about 394.1087978034.

The spelling of 61213666 in words is "sixty-one million, two hundred thirteen thousand, six hundred sixty-six".