61664379 has 16 divisors (see below), whose sum is σ = 94080000. Its totient is φ = 35193600.

The previous prime is 61664359. The next prime is 61664399. The reversal of 61664379 is 97346616.

It is an interprime number because it is at equal distance from previous prime (61664359) and next prime (61664399).

It is not a de Polignac number, because 61664379 - 2¹¹ = 61662331 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 61664379.

It is not an unprimeable number, because it can be changed into a prime (61664359) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 25054 + ... + 27404.

It is an arithmetic number, because the mean of its divisors is an integer number (5880000).

Almost surely, 2^61664379 is an apocalyptic number.

61664379 is a deficient number, since it is larger than the sum of its proper divisors (32415621).

61664379 is a wasteful number, since it uses less digits than its factorization.

61664379 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3610.

The product of its digits is 163296, while the sum is 42.

The square root of 61664379 is about 7852.6669991793. Note that the first 3 decimals coincide. The cubic root of 61664379 is about 395.0737009302.

The spelling of 61664379 in words is "sixty-one million, six hundred sixty-four thousand, three hundred seventy-nine".