997763521 has 2 divisors, whose sum is σ = 997763522. Its totient is φ = 997763520.

The previous prime is 997763479. The next prime is 997763527. The reversal of 997763521 is 125367799.

It is the 12896-th star number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 995087025 + 2676496 = 31545^2 + 1636^2 .

It is an emirp because it is prime and its reverse (125367799) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 997763521 - 2¹³ = 997755329 is a prime.

It is not a weakly prime, because it can be changed into another prime (997763527) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 498881760 + 498881761.

It is an arithmetic number, because the mean of its divisors is an integer number (498881761).

Almost surely, 2^997763521 is an apocalyptic number.

It is an amenable number.

997763521 is a deficient number, since it is larger than the sum of its proper divisors (1).

997763521 is an equidigital number, since it uses as much as digits as its factorization.

997763521 is an evil number, because the sum of its binary digits is even.

The product of its digits is 714420, while the sum is 49.

The square root of 997763521 is about 31587.3949701459. The cubic root of 997763521 is about 999.2539505486.

The spelling of 997763521 in words is "nine hundred ninety-seven million, seven hundred sixty-three thousand, five hundred twenty-one".