211431440 has 40 divisors (see below), whose sum is σ = 536269248. Its totient is φ = 76883840.

The previous prime is 211431421. The next prime is 211431443. The reversal of 211431440 is 44134112.

It is a tau number, because it is divible by the number of its divisors (40).

It is a Harshad number since it is a multiple of its sum of digits (20).

It is not an unprimeable number, because it can be changed into a prime (211431443) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 119252 + ... + 121011.

Almost surely, 2^211431440 is an apocalyptic number.

211431440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

211431440 is an abundant number, since it is smaller than the sum of its proper divisors (324837808).

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

211431440 is a wasteful number, since it uses less digits than its factorization.

211431440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 240287 (or 240281 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 20.

The square root of 211431440 is about 14540.6822398401. The cubic root of 211431440 is about 595.7396728042.

Adding to 211431440 its reverse (44134112), we get a palindrome (255565552).

The spelling of 211431440 in words is "two hundred eleven million, four hundred thirty-one thousand, four hundred forty".