131669639 has 4 divisors (see below), whose sum is σ = 138599640. Its totient is φ = 124739640.

The previous prime is 131669611. The next prime is 131669719. The reversal of 131669639 is 936966131.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 936966131 = 4637 ⋅202063.

It is a cyclic number.

It is not a de Polignac number, because 131669639 - 2¹⁶ = 131604103 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 131669639.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (131669609) 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, 3464972 + ... + 3465009.

It is an arithmetic number, because the mean of its divisors is an integer number (34649910).

Almost surely, 2^131669639 is an apocalyptic number.

131669639 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

131669639 is a deficient number, since it is larger than the sum of its proper divisors (6930001).

131669639 is an equidigital number, since it uses as much as digits as its factorization.

131669639 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6930000.

The product of its digits is 157464, while the sum is 44.

The square root of 131669639 is about 11474.7391691489. The cubic root of 131669639 is about 508.7392143355.

The spelling of 131669639 in words is "one hundred thirty-one million, six hundred sixty-nine thousand, six hundred thirty-nine".