64531261 has 16 divisors (see below), whose sum is σ = 69949440. Its totient is φ = 59376240.

The previous prime is 64531151. The next prime is 64531267. The reversal of 64531261 is 16213546.

It is a cyclic number.

It is not a de Polignac number, because 64531261 - 2⁹ = 64530749 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64531267) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 69760 + ... + 70678.

It is an arithmetic number, because the mean of its divisors is an integer number (4371840).

Almost surely, 2^64531261 is an apocalyptic number.

It is an amenable number.

64531261 is a deficient number, since it is larger than the sum of its proper divisors (5418179).

64531261 is a wasteful number, since it uses less digits than its factorization.

64531261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1056.

The product of its digits is 4320, while the sum is 28.

The square root of 64531261 is about 8033.1351911940. The cubic root of 64531261 is about 401.1037453144.

The spelling of 64531261 in words is "sixty-four million, five hundred thirty-one thousand, two hundred sixty-one".