215541472381 has 4 divisors (see below), whose sum is σ = 217186827264. Its totient is φ = 213896117500.

The previous prime is 215541472339. The next prime is 215541472427. The reversal of 215541472381 is 183274145512.

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 not a de Polignac number, because 215541472381 - 2⁷ = 215541472253 is a prime.

It is a super-2 number, since 2×215541472381² (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 (215541412381) 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, 822677245 + ... + 822677506.

It is an arithmetic number, because the mean of its divisors is an integer number (54296706816).

Almost surely, 2^215541472381 is an apocalyptic number.

It is an amenable number.

215541472381 is a deficient number, since it is larger than the sum of its proper divisors (1645354883).

215541472381 is a wasteful number, since it uses less digits than its factorization.

215541472381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1645354882.

The product of its digits is 268800, while the sum is 43.

The spelling of 215541472381 in words is "two hundred fifteen billion, five hundred forty-one million, four hundred seventy-two thousand, three hundred eighty-one".