213865551936 has 147 divisors (see below), whose sum is σ = 636590438653. Its totient is φ = 71255220480.

The previous prime is 213865551931. The next prime is 213865551937. The reversal of 213865551936 is 639155568312.

The square root of 213865551936 is 462456.

It is a perfect power (a square), and thus also a powerful number.

213865551936 is a `hidden beast` number, since 2 + 1 + 3 + 86 + 5 + 551 + 9 + 3 + 6 = 666.

It can be written as a sum of positive squares in only one way, i.e., 203993142336 + 9872409600 = 451656^2 + 99360^2 .

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

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (213865551931) by changing a digit.

It is a polite number, since it can be written in 20 ways as a sum of consecutive naturals, for example, 99889426 + ... + 99891566.

Almost surely, 2^213865551936 is an apocalyptic number.

213865551936 is the 462456-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 213865551936

213865551936 is an abundant number, since it is smaller than the sum of its proper divisors (422724886717).

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

213865551936 is an frugal number, since it uses more digits than its factorization.

213865551936 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4312 (or 2146 counting only the distinct ones).

The product of its digits is 5832000, while the sum is 54.

The spelling of 213865551936 in words is "two hundred thirteen billion, eight hundred sixty-five million, five hundred fifty-one thousand, nine hundred thirty-six".