64969421881 has 27 divisors (see below), whose sum is σ = 81866691693. Its totient is φ = 51386025600.

The previous prime is 64969421873. The next prime is 64969421911. The reversal of 64969421881 is 18812496946.

The square root of 64969421881 is 254891.

It is a perfect power (a square), and thus also a powerful number.

64969421881 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 8950106025 + 56019315856 = 94605^2 + 236684^2 .

It is not a de Polignac number, because 64969421881 - 2³ = 64969421873 is a prime.

It is a super-2 number, since 2×64969421881² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (64969421801) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 23193681 + ... + 23196481.

Almost surely, 2^64969421881 is an apocalyptic number.

64969421881 is the 254891-st square number.

64969421881 is the 127446-th centered octagonal number.

It is an amenable number.

64969421881 is a deficient number, since it is larger than the sum of its proper divisors (16897269812).

64969421881 is an frugal number, since it uses more digits than its factorization.

64969421881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5642 (or 2821 counting only the distinct ones).

The product of its digits is 5971968, while the sum is 58.

The spelling of 64969421881 in words is "sixty-four billion, nine hundred sixty-nine million, four hundred twenty-one thousand, eight hundred eighty-one".