64691077314820 has 96 divisors (see below), whose sum is σ = 151848701174016. Its totient is φ = 22945334630400.

The previous prime is 64691077314803. The next prime is 64691077314823. The reversal of 64691077314820 is 2841377019646.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (64691077314823) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 41291232 + ... + 42829288.

It is an arithmetic number, because the mean of its divisors is an integer number (1581757303896).

Almost surely, 2^{64691077314820} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 64691077314820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (75924350587008).

64691077314820 is an abundant number, since it is smaller than the sum of its proper divisors (87157623859196).

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

64691077314820 is a wasteful number, since it uses less digits than its factorization.

64691077314820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1542781 (or 1542779 counting only the distinct ones).

The product of its (nonzero) digits is 12192768, while the sum is 58.

The spelling of 64691077314820 in words is "sixty-four trillion, six hundred ninety-one billion, seventy-seven million, three hundred fourteen thousand, eight hundred twenty".