64121261 has 4 divisors (see below), whose sum is σ = 64359900. Its totient is φ = 63882624.

The previous prime is 64121249. The next prime is 64121269. The reversal of 64121261 is 16212146.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 16212146 = 2 ⋅8106073.

It can be written as a sum of positive squares in 2 ways, for example, as 38365636 + 25755625 = 6194^2 + 5075^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-64121261 is a prime.

It is a super-2 number, since 2×64121261² = 8223072224460242, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64121269) 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, 118916 + ... + 119453.

It is an arithmetic number, because the mean of its divisors is an integer number (16089975).

Almost surely, 2^64121261 is an apocalyptic number.

It is an amenable number.

64121261 is a deficient number, since it is larger than the sum of its proper divisors (238639).

64121261 is a wasteful number, since it uses less digits than its factorization.

64121261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 238638.

The product of its digits is 576, while the sum is 23.

The square root of 64121261 is about 8007.5752259969. The cubic root of 64121261 is about 400.2524677000.

The spelling of 64121261 in words is "sixty-four million, one hundred twenty-one thousand, two hundred sixty-one".