64521551 has 2 divisors, whose sum is σ = 64521552. Its totient is φ = 64521550.

The previous prime is 64521539. The next prime is 64521559. The reversal of 64521551 is 15512546.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 64521551 - 2⁶ = 64521487 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (64521559) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32260775 + 32260776.

It is an arithmetic number, because the mean of its divisors is an integer number (32260776).

Almost surely, 2^64521551 is an apocalyptic number.

64521551 is a deficient number, since it is larger than the sum of its proper divisors (1).

64521551 is an equidigital number, since it uses as much as digits as its factorization.

64521551 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6000, while the sum is 29.

The square root of 64521551 is about 8032.5307967041. The cubic root of 64521551 is about 401.0836263174.

The spelling of 64521551 in words is "sixty-four million, five hundred twenty-one thousand, five hundred fifty-one".