151638989 has 4 divisors (see below), whose sum is σ = 154500156. Its totient is φ = 148777824.

The previous prime is 151638979. The next prime is 151639003. The reversal of 151638989 is 989836151.

It is a happy number.

151638989 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 989836151 = 3701 ⋅267451.

It can be written as a sum of positive squares in 2 ways, for example, as 86304100 + 65334889 = 9290^2 + 8083^2 .

It is a cyclic number.

It is not a de Polignac number, because 151638989 - 2⁸ = 151638733 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 (151638959) 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, 1430504 + ... + 1430609.

It is an arithmetic number, because the mean of its divisors is an integer number (38625039).

Almost surely, 2^151638989 is an apocalyptic number.

It is an amenable number.

151638989 is a deficient number, since it is larger than the sum of its proper divisors (2861167).

151638989 is an equidigital number, since it uses as much as digits as its factorization.

151638989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2861166.

The product of its digits is 466560, while the sum is 50.

The square root of 151638989 is about 12314.1783729163. The cubic root of 151638989 is about 533.2574850036.

The spelling of 151638989 in words is "one hundred fifty-one million, six hundred thirty-eight thousand, nine hundred eighty-nine".