211421440 has 36 divisors (see below), whose sum is σ = 506423484. Its totient is φ = 84568064.

The previous prime is 211421437. The next prime is 211421443. The reversal of 211421440 is 44124112.

It is an interprime number because it is at equal distance from previous prime (211421437) and next prime (211421443).

It can be written as a sum of positive squares in 2 ways, for example, as 56070144 + 155351296 = 7488^2 + 12464^2 .

It is not an unprimeable number, because it can be changed into a prime (211421443) 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, 81307 + ... + 83866.

It is an arithmetic number, because the mean of its divisors is an integer number (14067319).

Almost surely, 2^211421440 is an apocalyptic number.

211421440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

211421440 is an abundant number, since it is smaller than the sum of its proper divisors (295002044).

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

211421440 is an equidigital number, since it uses as much as digits as its factorization.

211421440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 165194 (or 165180 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 19.

The square root of 211421440 is about 14540.3383729540. The cubic root of 211421440 is about 595.7302804914.

Adding to 211421440 its reverse (44124112), we get a palindrome (255545552).

The spelling of 211421440 in words is "two hundred eleven million, four hundred twenty-one thousand, four hundred forty".