194138021 has 8 divisors (see below), whose sum is σ = 242042304. Its totient is φ = 151276320.

The previous prime is 194138017. The next prime is 194138023. The reversal of 194138021 is 120831491.

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

It is a cyclic number.

It is not a de Polignac number, because 194138021 - 2² = 194138017 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (194138023) 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, 1260560 + ... + 1260713.

It is an arithmetic number, because the mean of its divisors is an integer number (30255288).

Almost surely, 2^194138021 is an apocalyptic number.

194138021 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

194138021 is a deficient number, since it is larger than the sum of its proper divisors (47904283).

194138021 is a wasteful number, since it uses less digits than its factorization.

194138021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2521291.

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

The square root of 194138021 is about 13933.3420614008. The cubic root of 194138021 is about 579.0332895589.

The spelling of 194138021 in words is "one hundred ninety-four million, one hundred thirty-eight thousand, twenty-one".