64155551 has 2 divisors, whose sum is σ = 64155552. Its totient is φ = 64155550.

The previous prime is 64155491. The next prime is 64155557. The reversal of 64155551 is 15555146.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 64155551 - 2¹⁸ = 63893407 is a prime.

It is a super-2 number, since 2×64155551² = 8231869448227202, which contains 22 as substring.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (64155557) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32077775 + 32077776.

It is an arithmetic number, because the mean of its divisors is an integer number (32077776).

Almost surely, 2^64155551 is an apocalyptic number.

64155551 is a deficient number, since it is larger than the sum of its proper divisors (1).

64155551 is an equidigital number, since it uses as much as digits as its factorization.

64155551 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 15000, while the sum is 32.

The square root of 64155551 is about 8009.7160374136. The cubic root of 64155551 is about 400.3238023926.

The spelling of 64155551 in words is "sixty-four million, one hundred fifty-five thousand, five hundred fifty-one".