131621405 has 4 divisors (see below), whose sum is σ = 157945692. Its totient is φ = 105297120.

The previous prime is 131621393. The next prime is 131621423. The reversal of 131621405 is 504126131.

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

It can be written as a sum of positive squares in 2 ways, for example, as 20403289 + 111218116 = 4517^2 + 10546^2 .

It is not a de Polignac number, because 131621405 - 2¹⁶ = 131555869 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13162136 + ... + 13162145.

It is an arithmetic number, because the mean of its divisors is an integer number (39486423).

Almost surely, 2^131621405 is an apocalyptic number.

It is an amenable number.

131621405 is a deficient number, since it is larger than the sum of its proper divisors (26324287).

131621405 is an equidigital number, since it uses as much as digits as its factorization.

131621405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26324286.

The product of its (nonzero) digits is 720, while the sum is 23.

The square root of 131621405 is about 11472.6372295127. The cubic root of 131621405 is about 508.6770852969.

Adding to 131621405 its reverse (504126131), we get a palindrome (635747536).

The spelling of 131621405 in words is "one hundred thirty-one million, six hundred twenty-one thousand, four hundred five".