131609421 has 16 divisors (see below), whose sum is σ = 195153600. Its totient is φ = 87660144.

The previous prime is 131609419. The next prime is 131609431. The reversal of 131609421 is 124906131.

131609421 is a `hidden beast` number, since 1 + 31 + 609 + 4 + 21 = 666.

It is not a de Polignac number, because 131609421 - 2¹ = 131609419 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (131609431) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 57715 + ... + 59951.

It is an arithmetic number, because the mean of its divisors is an integer number (12197100).

Almost surely, 2^131609421 is an apocalyptic number.

It is an amenable number.

131609421 is a deficient number, since it is larger than the sum of its proper divisors (63544179).

131609421 is a wasteful number, since it uses less digits than its factorization.

131609421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4425 (or 4419 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 27.

The square root of 131609421 is about 11472.1149314327. The cubic root of 131609421 is about 508.6616466449.

The spelling of 131609421 in words is "one hundred thirty-one million, six hundred nine thousand, four hundred twenty-one".