64490761281 has 16 divisors (see below), whose sum is σ = 91055337408. Its totient is φ = 40460544000.

The previous prime is 64490761253. The next prime is 64490761331. The reversal of 64490761281 is 18216709446.

64490761281 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 64490761281 - 2¹⁷ = 64490630209 is a prime.

It is a super-2 number, since 2×64490761281² (a number of 22 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 64490761281.

It is not an unprimeable number, because it can be changed into a prime (64490761211) 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, 465681 + ... + 588081.

It is an arithmetic number, because the mean of its divisors is an integer number (5690958588).

Almost surely, 2^64490761281 is an apocalyptic number.

It is an amenable number.

64490761281 is a deficient number, since it is larger than the sum of its proper divisors (26564576127).

64490761281 is a wasteful number, since it uses less digits than its factorization.

64490761281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 132752.

The product of its (nonzero) digits is 580608, while the sum is 48.

The spelling of 64490761281 in words is "sixty-four billion, four hundred ninety million, seven hundred sixty-one thousand, two hundred eighty-one".