997260661 has 4 divisors (see below), whose sum is σ = 997506432. Its totient is φ = 997014892.

The previous prime is 997260631. The next prime is 997260673. The reversal of 997260661 is 166062799.

997260661 = T₂₅₇₈₃ + T₂₅₇₈₄ + T₂₅₇₈₅.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 166062799 = 7 ⋅23723257.

It is a cyclic number.

It is not a de Polignac number, because 997260661 - 2¹⁵ = 997227893 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (997260631) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 116695 + ... + 124948.

It is an arithmetic number, because the mean of its divisors is an integer number (249376608).

Almost surely, 2^997260661 is an apocalyptic number.

997260661 is the 25785-th centered triangular number.

It is an amenable number.

997260661 is a deficient number, since it is larger than the sum of its proper divisors (245771).

997260661 is a wasteful number, since it uses less digits than its factorization.

997260661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 245770.

The product of its (nonzero) digits is 244944, while the sum is 46.

The square root of 997260661 is about 31579.4341462921. The cubic root of 997260661 is about 999.0860519534.

The spelling of 997260661 in words is "nine hundred ninety-seven million, two hundred sixty thousand, six hundred sixty-one".