215447438197 has 4 divisors (see below), whose sum is σ = 215449650400. Its totient is φ = 215445225996.

The previous prime is 215447438153. The next prime is 215447438221. The reversal of 215447438197 is 791834744512.

It is a happy number.

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.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-215447438197 is a prime.

It is a super-2 number, since 2×215447438197² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (215447438897) 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, 952947 + ... + 1157152.

It is an arithmetic number, because the mean of its divisors is an integer number (53862412600).

Almost surely, 2^215447438197 is an apocalyptic number.

It is an amenable number.

215447438197 is a deficient number, since it is larger than the sum of its proper divisors (2212203).

215447438197 is a wasteful number, since it uses less digits than its factorization.

215447438197 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2212202.

The product of its digits is 6773760, while the sum is 55.

The spelling of 215447438197 in words is "two hundred fifteen billion, four hundred forty-seven million, four hundred thirty-eight thousand, one hundred ninety-seven".