64723121 has 4 divisors (see below), whose sum is σ = 64754292. Its totient is φ = 64691952.

The previous prime is 64723117. The next prime is 64723147. The reversal of 64723121 is 12132746.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 43230625 + 21492496 = 6575^2 + 4636^2 .

It is a cyclic number.

It is not a de Polignac number, because 64723121 - 2² = 64723117 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (64723171) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12230 + ... + 16703.

It is an arithmetic number, because the mean of its divisors is an integer number (16188573).

Almost surely, 2^64723121 is an apocalyptic number.

It is an amenable number.

64723121 is a deficient number, since it is larger than the sum of its proper divisors (31171).

64723121 is a wasteful number, since it uses less digits than its factorization.

64723121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31170.

The product of its digits is 2016, while the sum is 26.

The square root of 64723121 is about 8045.0681165544. The cubic root of 64723121 is about 401.5008635614.

Adding to 64723121 its reverse (12132746), we get a palindrome (76855867).

The spelling of 64723121 in words is "sixty-four million, seven hundred twenty-three thousand, one hundred twenty-one".