381212129 has 4 divisors (see below), whose sum is σ = 381283584. Its totient is φ = 381140676.

The previous prime is 381212123. The next prime is 381212141. The reversal of 381212129 is 921212183.

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 381212129 - 2²⁴ = 364434913 is a prime.

It is an alternating number because its digits alternate between odd and even.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (381212123) 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, 27017 + ... + 38630.

It is an arithmetic number, because the mean of its divisors is an integer number (95320896).

Almost surely, 2^381212129 is an apocalyptic number.

It is an amenable number.

381212129 is a deficient number, since it is larger than the sum of its proper divisors (71455).

381212129 is an equidigital number, since it uses as much as digits as its factorization.

381212129 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 71454.

The product of its digits is 1728, while the sum is 29.

The square root of 381212129 is about 19524.6543887466. The cubic root of 381212129 is about 725.0849707782.

The spelling of 381212129 in words is "three hundred eighty-one million, two hundred twelve thousand, one hundred twenty-nine".