136471981 has 4 divisors (see below), whose sum is σ = 139645792. Its totient is φ = 133298172.

The previous prime is 136471969. The next prime is 136471991. The reversal of 136471981 is 189174631.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 136471981 - 2⁹ = 136471469 is a prime.

It is a super-3 number, since 3×136471981³ (a number of 25 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (136471901) 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, 1586841 + ... + 1586926.

It is an arithmetic number, because the mean of its divisors is an integer number (34911448).

Almost surely, 2^136471981 is an apocalyptic number.

It is an amenable number.

136471981 is a deficient number, since it is larger than the sum of its proper divisors (3173811).

136471981 is an equidigital number, since it uses as much as digits as its factorization.

136471981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3173810.

The product of its digits is 36288, while the sum is 40.

The square root of 136471981 is about 11682.1222815035. The cubic root of 136471981 is about 514.8505312931.

The spelling of 136471981 in words is "one hundred thirty-six million, four hundred seventy-one thousand, nine hundred eighty-one".