197638581 has 16 divisors (see below), whose sum is σ = 301377024. Its totient is φ = 112856304.

The previous prime is 197638559. The next prime is 197638591. The reversal of 197638581 is 185836791.

It is not a de Polignac number, because 197638581 - 2⁷ = 197638453 is a prime.

It is a super-2 number, since 2×197638581² = 78122017399387122, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 197638581.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (197638501) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 40246 + ... + 44888.

It is an arithmetic number, because the mean of its divisors is an integer number (18836064).

Almost surely, 2^197638581 is an apocalyptic number.

It is an amenable number.

197638581 is a deficient number, since it is larger than the sum of its proper divisors (103738443).

197638581 is a wasteful number, since it uses less digits than its factorization.

197638581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6680.

The product of its digits is 362880, while the sum is 48.

The square root of 197638581 is about 14058.3989486712. The cubic root of 197638581 is about 582.4928189601.

The spelling of 197638581 in words is "one hundred ninety-seven million, six hundred thirty-eight thousand, five hundred eighty-one".