231220501 has 4 divisors (see below), whose sum is σ = 233341900. Its totient is φ = 229099104.

The previous prime is 231220489. The next prime is 231220513. The reversal of 231220501 is 105022132.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (231220489) and next prime (231220513).

It can be written as a sum of positive squares in 2 ways, for example, as 147039876 + 84180625 = 12126^2 + 9175^2 .

It is a cyclic number.

It is not a de Polignac number, because 231220501 - 2¹³ = 231212309 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (231220001) 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, 1060536 + ... + 1060753.

It is an arithmetic number, because the mean of its divisors is an integer number (58335475).

Almost surely, 2^231220501 is an apocalyptic number.

It is an amenable number.

231220501 is a deficient number, since it is larger than the sum of its proper divisors (2121399).

231220501 is a wasteful number, since it uses less digits than its factorization.

231220501 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2121398.

The product of its (nonzero) digits is 120, while the sum is 16.

The square root of 231220501 is about 15205.9363736667. The cubic root of 231220501 is about 613.7744125248.

Adding to 231220501 its reverse (105022132), we get a palindrome (336242633).

The spelling of 231220501 in words is "two hundred thirty-one million, two hundred twenty thousand, five hundred one".