921565397 has 2 divisors, whose sum is σ = 921565398. Its totient is φ = 921565396.

The previous prime is 921565349. The next prime is 921565423. The reversal of 921565397 is 793565129.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 852990436 + 68574961 = 29206^2 + 8281^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-921565397 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (921565097) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 460782698 + 460782699.

It is an arithmetic number, because the mean of its divisors is an integer number (460782699).

Almost surely, 2^921565397 is an apocalyptic number.

It is an amenable number.

921565397 is a deficient number, since it is larger than the sum of its proper divisors (1).

921565397 is an equidigital number, since it uses as much as digits as its factorization.

921565397 is an evil number, because the sum of its binary digits is even.

The product of its digits is 510300, while the sum is 47.

The square root of 921565397 is about 30357.2956140694. The cubic root of 921565397 is about 973.1401396002.

The spelling of 921565397 in words is "nine hundred twenty-one million, five hundred sixty-five thousand, three hundred ninety-seven".