231621620 has 12 divisors (see below), whose sum is σ = 486405444. Its totient is φ = 92648640.

The previous prime is 231621581. The next prime is 231621623. The reversal of 231621620 is 26126132.

It can be written as a sum of positive squares in 2 ways, for example, as 137686756 + 93934864 = 11734^2 + 9692^2 .

It is a super-3 number, since 3×231621620³ (a number of 26 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (231621623) 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, 5790521 + ... + 5790560.

It is an arithmetic number, because the mean of its divisors is an integer number (40533787).

Almost surely, 2^231621620 is an apocalyptic number.

231621620 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

231621620 is an abundant number, since it is smaller than the sum of its proper divisors (254783824).

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

231621620 is a wasteful number, since it uses less digits than its factorization.

231621620 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11581090 (or 11581088 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 23.

The square root of 231621620 is about 15219.1202111029. The cubic root of 231621620 is about 614.1291307096.

Adding to 231621620 its reverse (26126132), we get a palindrome (257747752).

The spelling of 231621620 in words is "two hundred thirty-one million, six hundred twenty-one thousand, six hundred twenty".