211725381 has 16 divisors (see below), whose sum is σ = 333037568. Its totient is φ = 117082800.

The previous prime is 211725329. The next prime is 211725403. The reversal of 211725381 is 183527112.

211725381 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 211725381 - 2¹¹ = 211723333 is a prime.

It is a super-2 number, since 2×211725381² = 89655273919190322, which contains 22 as substring.

It is a Smith number, since the sum of its digits (30) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (211725181) 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, 161965 + ... + 163266.

It is an arithmetic number, because the mean of its divisors is an integer number (20814848).

Almost surely, 2^211725381 is an apocalyptic number.

211725381 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

211725381 is a deficient number, since it is larger than the sum of its proper divisors (121312187).

211725381 is a wasteful number, since it uses less digits than its factorization.

211725381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 325272.

The product of its digits is 3360, while the sum is 30.

The square root of 211725381 is about 14550.7862674152. The cubic root of 211725381 is about 596.0156191949.

The spelling of 211725381 in words is "two hundred eleven million, seven hundred twenty-five thousand, three hundred eighty-one".