211231404 has 18 divisors (see below), whose sum is σ = 533946140. Its totient is φ = 70410456.

The previous prime is 211231403. The next prime is 211231429. The reversal of 211231404 is 404132112.

It is a tau number, because it is divible by the number of its divisors (18).

It is a super-2 number, since 2×211231404² = 89237412071622432, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is not an unprimeable number, because it can be changed into a prime (211231403) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 2933734 + ... + 2933805.

Almost surely, 2^211231404 is an apocalyptic number.

It is an amenable number.

211231404 is an abundant number, since it is smaller than the sum of its proper divisors (322714736).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

211231404 is a wasteful number, since it uses less digits than its factorization.

211231404 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5867549 (or 5867544 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 18.

The square root of 211231404 is about 14533.8021178218. The cubic root of 211231404 is about 595.5517364166.

Adding to 211231404 its reverse (404132112), we get a palindrome (615363516).

The spelling of 211231404 in words is "two hundred eleven million, two hundred thirty-one thousand, four hundred four".