64242676781 has 8 divisors (see below), whose sum is σ = 66190254840. Its totient is φ = 62322337792.

The previous prime is 64242676753. The next prime is 64242676787. The reversal of 64242676781 is 18767624246.

It can be written as a sum of positive squares in 4 ways, for example, as 13979278756 + 50263398025 = 118234^2 + 224195^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 64242676781 - 2¹⁸ = 64242414637 is a prime.

It is a super-2 number, since 2×64242676781² (a number of 22 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (53).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64242676787) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6804980 + ... + 6814413.

It is an arithmetic number, because the mean of its divisors is an integer number (8273781855).

Almost surely, 2^64242676781 is an apocalyptic number.

It is an amenable number.

64242676781 is a deficient number, since it is larger than the sum of its proper divisors (1947578059).

64242676781 is a wasteful number, since it uses less digits than its factorization.

64242676781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13619535.

The product of its digits is 5419008, while the sum is 53.

The spelling of 64242676781 in words is "sixty-four billion, two hundred forty-two million, six hundred seventy-six thousand, seven hundred eighty-one".