61405666 has 32 divisors (see below), whose sum is σ = 113374080. Its totient is φ = 24343296.

The previous prime is 61405657. The next prime is 61405667. The reversal of 61405666 is 66650416.

It is a Harshad number since it is a multiple of its sum of digits (34).

It is not an unprimeable number, because it can be changed into a prime (61405667) 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, 11856 + ... + 16228.

It is an arithmetic number, because the mean of its divisors is an integer number (3542940).

Almost surely, 2^61405666 is an apocalyptic number.

61405666 is a deficient number, since it is larger than the sum of its proper divisors (51968414).

61405666 is a wasteful number, since it uses less digits than its factorization.

61405666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4458.

The product of its (nonzero) digits is 25920, while the sum is 34.

The square root of 61405666 is about 7836.1767463477. The cubic root of 61405666 is about 394.5204156576.

The spelling of 61405666 in words is "sixty-one million, four hundred five thousand, six hundred sixty-six".