997507501 has 2 divisors, whose sum is σ = 997507502. Its totient is φ = 997507500.

The previous prime is 997507499. The next prime is 997507571. The reversal of 997507501 is 105705799.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 533148100 + 464359401 = 23090^2 + 21549^2 .

It is an emirp because it is prime and its reverse (105705799) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 997507501 - 2¹ = 997507499 is a prime.

Together with 997507499, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (997507571) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 498753750 + 498753751.

It is an arithmetic number, because the mean of its divisors is an integer number (498753751).

Almost surely, 2^997507501 is an apocalyptic number.

997507501 is the 14125-th centered decagonal number.

It is an amenable number.

997507501 is a deficient number, since it is larger than the sum of its proper divisors (1).

997507501 is an equidigital number, since it uses as much as digits as its factorization.

997507501 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 99225, while the sum is 43.

The square root of 997507501 is about 31583.3421442380. The cubic root of 997507501 is about 999.1684757591.

It can be divided in two parts, 99 and 7507501, that added together give a square (7507600 = 2740²).

The spelling of 997507501 in words is "nine hundred ninety-seven million, five hundred seven thousand, five hundred one".