309801997 has 4 divisors (see below), whose sum is σ = 310004320. Its totient is φ = 309599676.

The previous prime is 309801967. The next prime is 309802091. The reversal of 309801997 is 799108903.

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: 799108903 = 149 ⋅5363147.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-309801997 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 (309801937) 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, 98847 + ... + 101932.

It is an arithmetic number, because the mean of its divisors is an integer number (77501080).

Almost surely, 2^309801997 is an apocalyptic number.

It is an amenable number.

309801997 is a deficient number, since it is larger than the sum of its proper divisors (202323).

309801997 is a wasteful number, since it uses less digits than its factorization.

309801997 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 202322.

The product of its (nonzero) digits is 122472, while the sum is 46.

The square root of 309801997 is about 17601.1930561539. The cubic root of 309801997 is about 676.6458215758.

The spelling of 309801997 in words is "three hundred nine million, eight hundred one thousand, nine hundred ninety-seven".