64136881 has 2 divisors, whose sum is σ = 64136882. Its totient is φ = 64136880.

The previous prime is 64136867. The next prime is 64136887. The reversal of 64136881 is 18863146.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 59367025 + 4769856 = 7705^2 + 2184^2 .

It is a cyclic number.

It is not a de Polignac number, because 64136881 - 2⁷ = 64136753 is a prime.

It is a super-2 number, since 2×64136881² = 8227079008816322, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 64136881.

It is not a weakly prime, because it can be changed into another prime (64136887) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32068440 + 32068441.

It is an arithmetic number, because the mean of its divisors is an integer number (32068441).

Almost surely, 2^64136881 is an apocalyptic number.

It is an amenable number.

64136881 is a deficient number, since it is larger than the sum of its proper divisors (1).

64136881 is an equidigital number, since it uses as much as digits as its factorization.

64136881 is an evil number, because the sum of its binary digits is even.

The product of its digits is 27648, while the sum is 37.

The square root of 64136881 is about 8008.5504930668. The cubic root of 64136881 is about 400.2849656882.

The spelling of 64136881 in words is "sixty-four million, one hundred thirty-six thousand, eight hundred eighty-one".