64987777 has 2 divisors, whose sum is σ = 64987778. Its totient is φ = 64987776.

The previous prime is 64987759. The next prime is 64987781. The reversal of 64987777 is 77778946.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 51854401 + 13133376 = 7201^2 + 3624^2 .

It is a cyclic number.

It is not a de Polignac number, because 64987777 - 2¹¹ = 64985729 is a prime.

It is a super-2 number, since 2×64987777² = 8446822318803458, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (64987757) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32493888 + 32493889.

It is an arithmetic number, because the mean of its divisors is an integer number (32493889).

Almost surely, 2^64987777 is an apocalyptic number.

It is an amenable number.

64987777 is a deficient number, since it is larger than the sum of its proper divisors (1).

64987777 is an equidigital number, since it uses as much as digits as its factorization.

64987777 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4148928, while the sum is 55.

The square root of 64987777 is about 8061.4996743782. The cubic root of 64987777 is about 402.0473715452.

The spelling of 64987777 in words is "sixty-four million, nine hundred eighty-seven thousand, seven hundred seventy-seven".