64217134921 has 9 divisors (see below), whose sum is σ = 64576692999. Its totient is φ = 63859572000.

The previous prime is 64217134913. The next prime is 64217134951. The reversal of 64217134921 is 12943171246.

The square root of 64217134921 is 253411.

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

It can be written as a sum of positive squares in only one way, i.e., 106894921 + 64110240000 = 10339^2 + 253200^2 .

It is not a de Polignac number, because 64217134921 - 2³ = 64217134913 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (64217134951) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 53469121 + ... + 53470321.

It is an arithmetic number, because the mean of its divisors is an integer number (7175188111).

Almost surely, 2^64217134921 is an apocalyptic number.

64217134921 is the 253411-st square number.

64217134921 is the 126706-th centered octagonal number.

It is an amenable number.

64217134921 is a deficient number, since it is larger than the sum of its proper divisors (359558078).

64217134921 is an frugal number, since it uses more digits than its factorization.

64217134921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2824 (or 1412 counting only the distinct ones).

The product of its digits is 72576, while the sum is 40.

The spelling of 64217134921 in words is "sixty-four billion, two hundred seventeen million, one hundred thirty-four thousand, nine hundred twenty-one".