213861229520 has 40 divisors (see below), whose sum is σ = 497436633000. Its totient is φ = 85508487680.

The previous prime is 213861229499. The next prime is 213861229537. The reversal of 213861229520 is 25922168312.

It can be written as a sum of positive squares in 4 ways, for example, as 33113808784 + 180747420736 = 181972^2 + 425144^2 .

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

It is a super-2 number, since 2×213861229520² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 370895 + ... + 751854.

It is an arithmetic number, because the mean of its divisors is an integer number (12435915825).

Almost surely, 2^213861229520 is an apocalyptic number.

213861229520 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

213861229520 is an abundant number, since it is smaller than the sum of its proper divisors (283575403480).

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

213861229520 is a wasteful number, since it uses less digits than its factorization.

213861229520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1125143 (or 1125137 counting only the distinct ones).

The product of its (nonzero) digits is 103680, while the sum is 41.

The spelling of 213861229520 in words is "two hundred thirteen billion, eight hundred sixty-one million, two hundred twenty-nine thousand, five hundred twenty".