138420291 has 8 divisors (see below), whose sum is σ = 184616464. Its totient is φ = 92252160.

The previous prime is 138420283. The next prime is 138420323. The reversal of 138420291 is 192024831.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 138420291 - 2³ = 138420283 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (138420091) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11475 + ... + 20211.

It is an arithmetic number, because the mean of its divisors is an integer number (23077058).

Almost surely, 2^138420291 is an apocalyptic number.

138420291 is a deficient number, since it is larger than the sum of its proper divisors (46196173).

138420291 is an equidigital number, since it uses as much as digits as its factorization.

138420291 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14021.

The product of its (nonzero) digits is 3456, while the sum is 30.

The square root of 138420291 is about 11765.2152976476. The cubic root of 138420291 is about 517.2890110516.

The spelling of 138420291 in words is "one hundred thirty-eight million, four hundred twenty thousand, two hundred ninety-one".