64142561 has 16 divisors (see below), whose sum is σ = 77946624. Its totient is φ = 51589824.

The previous prime is 64142557. The next prime is 64142587. The reversal of 64142561 is 16524146.

It is a cyclic number.

It is not a de Polignac number, because 64142561 - 2² = 64142557 is a prime.

It is a super-2 number, since 2×64142561² = 8228536263277442, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (64142501) 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, 4775 + ... + 12291.

It is an arithmetic number, because the mean of its divisors is an integer number (4871664).

Almost surely, 2^64142561 is an apocalyptic number.

It is an amenable number.

64142561 is a deficient number, since it is larger than the sum of its proper divisors (13804063).

64142561 is a wasteful number, since it uses less digits than its factorization.

64142561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7600.

The product of its digits is 5760, while the sum is 29.

The square root of 64142561 is about 8008.9051061927. The cubic root of 64142561 is about 400.2967818302.

The spelling of 64142561 in words is "sixty-four million, one hundred forty-two thousand, five hundred sixty-one".