139804421 has 2 divisors, whose sum is σ = 139804422. Its totient is φ = 139804420.

The previous prime is 139804403. The next prime is 139804429. The reversal of 139804421 is 124408931.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 137147521 + 2656900 = 11711^2 + 1630^2 .

It is an emirp because it is prime and its reverse (124408931) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 139804421 - 2²² = 135610117 is a prime.

It is a super-2 number, since 2×139804421² = 39090552262290482, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (139804429) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69902210 + 69902211.

It is an arithmetic number, because the mean of its divisors is an integer number (69902211).

Almost surely, 2^139804421 is an apocalyptic number.

It is an amenable number.

139804421 is a deficient number, since it is larger than the sum of its proper divisors (1).

139804421 is an equidigital number, since it uses as much as digits as its factorization.

139804421 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6912, while the sum is 32.

The square root of 139804421 is about 11823.8919565429. The cubic root of 139804421 is about 519.0075015962.

The spelling of 139804421 in words is "one hundred thirty-nine million, eight hundred four thousand, four hundred twenty-one".