197018639 has 4 divisors (see below), whose sum is σ = 197099856. Its totient is φ = 196937424.

The previous prime is 197018573. The next prime is 197018669. The reversal of 197018639 is 936810791.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 197018639 - 2⁸ = 197018383 is a prime.

It is a super-2 number, since 2×197018639² = 77632688226824642, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 197018639.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (197018669) 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, 36854 + ... + 41859.

It is an arithmetic number, because the mean of its divisors is an integer number (49274964).

Almost surely, 2^197018639 is an apocalyptic number.

197018639 is a deficient number, since it is larger than the sum of its proper divisors (81217).

197018639 is an equidigital number, since it uses as much as digits as its factorization.

197018639 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 81216.

The product of its (nonzero) digits is 81648, while the sum is 44.

The square root of 197018639 is about 14036.3328187957. The cubic root of 197018639 is about 581.8831370640.

The spelling of 197018639 in words is "one hundred ninety-seven million, eighteen thousand, six hundred thirty-nine".