64155121 has 4 divisors (see below), whose sum is σ = 64816612.
Its totient is φ = 63493632.
The previous prime is 64155109. The next prime is 64155131. The reversal of 64155121 is 12155146.
It is a happy number.
It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12155146 = 2 ⋅6077573.
It can be written as a sum of positive squares in 2 ways, for example, as 23386896 + 40768225 = 4836^2 + 6385^2
It is a cyclic number.
It is a de Polignac number, because none of the positive numbers 2k-64155121 is a prime.
It is a Duffinian number.
It is not an unprimeable number, because it can be changed into a prime (64155131) by changing a digit.
It is a pernicious number, because its binary representation contains a prime number (17) of ones.
It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 330600 + ... + 330793.
It is an arithmetic number, because the mean of its divisors is an integer number (16204153).
Almost surely, 264155121 is an apocalyptic number.
It is an amenable number.
64155121 is a deficient number, since it is larger than the sum of its proper divisors (661491).
64155121 is an equidigital number, since it uses as much as digits as its factorization.
64155121 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 661490.
The product of its digits is 1200, while the sum is 25.
The square root of 64155121 is about 8009.6891949688.
The cubic root of 64155121 is about 400.3229080059.
Adding to 64155121 its sum of digits (25), we get a palindrome (64155146).
The spelling of 64155121 in words is "sixty-four million, one hundred fifty-five thousand, one hundred twenty-one".