64401551 has 2 divisors, whose sum is σ = 64401552. Its totient is φ = 64401550.

The previous prime is 64401523. The next prime is 64401553. The reversal of 64401551 is 15510446.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-64401551 is a prime.

Together with 64401553, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 64401551.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (64401553) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32200775 + 32200776.

It is an arithmetic number, because the mean of its divisors is an integer number (32200776).

Almost surely, 2^64401551 is an apocalyptic number.

64401551 is a deficient number, since it is larger than the sum of its proper divisors (1).

64401551 is an equidigital number, since it uses as much as digits as its factorization.

64401551 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2400, while the sum is 26.

The square root of 64401551 is about 8025.0576944967. The cubic root of 64401551 is about 400.8348210557.

Adding to 64401551 its reverse (15510446), we get a palindrome (79911997).

The spelling of 64401551 in words is "sixty-four million, four hundred one thousand, five hundred fifty-one".