64497581 has 4 divisors (see below), whose sum is σ = 64677600. Its totient is φ = 64317564.

The previous prime is 64497569. The next prime is 64497593. The reversal of 64497581 is 18579446.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is an interprime number because it is at equal distance from previous prime (64497569) and next prime (64497593).

It is a cyclic number.

It is not a de Polignac number, because 64497581 - 2¹⁰ = 64496557 is a prime.

It is a super-2 number, since 2×64497581² = 8319875909703122, 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 (64497281) 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, 89471 + ... + 90188.

It is an arithmetic number, because the mean of its divisors is an integer number (16169400).

Almost surely, 2^64497581 is an apocalyptic number.

It is an amenable number.

64497581 is a deficient number, since it is larger than the sum of its proper divisors (180019).

64497581 is a wasteful number, since it uses less digits than its factorization.

64497581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 180018.

The product of its digits is 241920, while the sum is 44.

The square root of 64497581 is about 8031.0386003306. The cubic root of 64497581 is about 401.0339521380.

The spelling of 64497581 in words is "sixty-four million, four hundred ninety-seven thousand, five hundred eighty-one".