213909381 has 24 divisors (see below), whose sum is σ = 354267264. Its totient is φ = 121836960.

The previous prime is 213909379. The next prime is 213909401. The reversal of 213909381 is 183909312.

It is not a de Polignac number, because 213909381 - 2¹ = 213909379 is a prime.

It is a super-2 number, since 2×213909381² = 91514446559606322, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (213909781) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 14616 + ... + 25326.

It is an arithmetic number, because the mean of its divisors is an integer number (14761136).

Almost surely, 2^213909381 is an apocalyptic number.

213909381 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

213909381 is a deficient number, since it is larger than the sum of its proper divisors (140357883).

213909381 is a wasteful number, since it uses less digits than its factorization.

213909381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11041 (or 11038 counting only the distinct ones).

The product of its (nonzero) digits is 11664, while the sum is 36.

The square root of 213909381 is about 14625.6412167125. The cubic root of 213909381 is about 598.0579625998.

The spelling of 213909381 in words is "two hundred thirteen million, nine hundred nine thousand, three hundred eighty-one".