21871197237 has 16 divisors (see below), whose sum is σ = 30928341888. Its totient is φ = 13718210880.

The previous prime is 21871197181. The next prime is 21871197287. The reversal of 21871197237 is 73279117812.

It is not a de Polignac number, because 21871197237 - 2⁷ = 21871197109 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21871197287) 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, 2593938 + ... + 2602355.

It is an arithmetic number, because the mean of its divisors is an integer number (1933021368).

Almost surely, 2^21871197237 is an apocalyptic number.

It is an amenable number.

21871197237 is a deficient number, since it is larger than the sum of its proper divisors (9057144651).

21871197237 is a wasteful number, since it uses less digits than its factorization.

21871197237 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5196380.

The product of its digits is 296352, while the sum is 48.

The spelling of 21871197237 in words is "twenty-one billion, eight hundred seventy-one million, one hundred ninety-seven thousand, two hundred thirty-seven".