997951291 has 2 divisors, whose sum is σ = 997951292. Its totient is φ = 997951290.

The previous prime is 997951271. The next prime is 997951327. The reversal of 997951291 is 192159799.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 997951291 - 2⁵ = 997951259 is a prime.

It is not a weakly prime, because it can be changed into another prime (997951211) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 498975645 + 498975646.

It is an arithmetic number, because the mean of its divisors is an integer number (498975646).

Almost surely, 2^997951291 is an apocalyptic number.

997951291 is a deficient number, since it is larger than the sum of its proper divisors (1).

997951291 is an equidigital number, since it uses as much as digits as its factorization.

997951291 is an evil number, because the sum of its binary digits is even.

The product of its digits is 459270, while the sum is 52.

The square root of 997951291 is about 31590.3670602290. The cubic root of 997951291 is about 999.3166301120.

The spelling of 997951291 in words is "nine hundred ninety-seven million, nine hundred fifty-one thousand, two hundred ninety-one".