664042501 has 2 divisors, whose sum is σ = 664042502. Its totient is φ = 664042500.

The previous prime is 664042469. The next prime is 664042517. The reversal of 664042501 is 105240466.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 564062500 + 99980001 = 23750^2 + 9999^2 .

It is a cyclic number.

It is not a de Polignac number, because 664042501 - 2⁵ = 664042469 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 664042501.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (664042201) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332021250 + 332021251.

It is an arithmetic number, because the mean of its divisors is an integer number (332021251).

Almost surely, 2^664042501 is an apocalyptic number.

It is an amenable number.

664042501 is a deficient number, since it is larger than the sum of its proper divisors (1).

664042501 is an equidigital number, since it uses as much as digits as its factorization.

664042501 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5760, while the sum is 28.

The square root of 664042501 is about 25769.0221195916. The cubic root of 664042501 is about 872.4327475852.

Adding to 664042501 its reverse (105240466), we get a palindrome (769282967).

It can be divided in two parts, 6640 and 42501, that added together give a triangular number (49141 = T₃₁₃).

The spelling of 664042501 in words is "six hundred sixty-four million, forty-two thousand, five hundred one".