61819644 has 12 divisors (see below), whose sum is σ = 144245864. Its totient is φ = 20606544.

The previous prime is 61819643. The next prime is 61819661. The reversal of 61819644 is 44691816.

It is a tau number, because it is divible by the number of its divisors (12).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61819643) 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 3 ways as a sum of consecutive naturals, for example, 2575807 + ... + 2575830.

Almost surely, 2^61819644 is an apocalyptic number.

It is an amenable number.

61819644 is an abundant number, since it is smaller than the sum of its proper divisors (82426220).

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

61819644 is a wasteful number, since it uses less digits than its factorization.

61819644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5151644 (or 5151642 counting only the distinct ones).

The product of its digits is 41472, while the sum is 39.

The square root of 61819644 is about 7862.5469155993. The cubic root of 61819644 is about 395.4050089310.

The spelling of 61819644 in words is "sixty-one million, eight hundred nineteen thousand, six hundred forty-four".