213402440 has 16 divisors (see below), whose sum is σ = 480155580. Its totient is φ = 85360960.

The previous prime is 213402373. The next prime is 213402457. The reversal of 213402440 is 44204312.

It can be written as a sum of positive squares in 2 ways, for example, as 205234276 + 8168164 = 14326^2 + 2858^2 .

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2667491 + ... + 2667570.

Almost surely, 2^213402440 is an apocalyptic number.

213402440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

213402440 is an abundant number, since it is smaller than the sum of its proper divisors (266753140).

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

213402440 is a wasteful number, since it uses less digits than its factorization.

213402440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5335072 (or 5335068 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 20.

The square root of 213402440 is about 14608.3003802633. The cubic root of 213402440 is about 597.5851456888.

Adding to 213402440 its reverse (44204312), we get a palindrome (257606752).

The spelling of 213402440 in words is "two hundred thirteen million, four hundred two thousand, four hundred forty".