213857681544 has 128 divisors (see below), whose sum is σ = 641006352000. Its totient is φ = 65672646912.

The previous prime is 213857681537. The next prime is 213857681549. The reversal of 213857681544 is 445186758312.

It is a happy number.

213857681544 is a `hidden beast` number, since 2 + 1 + 38 + 5 + 7 + 68 + 1 + 544 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is not an unprimeable number, because it can be changed into a prime (213857681549) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1354459 + ... + 1504085.

It is an arithmetic number, because the mean of its divisors is an integer number (5007862125).

Almost surely, 2^213857681544 is an apocalyptic number.

213857681544 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 213857681544, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (320503176000).

213857681544 is an abundant number, since it is smaller than the sum of its proper divisors (427148670456).

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

213857681544 is a wasteful number, since it uses less digits than its factorization.

213857681544 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 150164 (or 150154 counting only the distinct ones).

The product of its digits is 6451200, while the sum is 54.

The spelling of 213857681544 in words is "two hundred thirteen billion, eight hundred fifty-seven million, six hundred eighty-one thousand, five hundred forty-four".