156904421 has 2 divisors, whose sum is σ = 156904422. Its totient is φ = 156904420.

The previous prime is 156904403. The next prime is 156904439. The reversal of 156904421 is 124409651.

It is a balanced prime because it is at equal distance from previous prime (156904403) and next prime (156904439).

It can be written as a sum of positive squares in only one way, i.e., 113529025 + 43375396 = 10655^2 + 6586^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-156904421 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (156904481) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 78452210 + 78452211.

It is an arithmetic number, because the mean of its divisors is an integer number (78452211).

Almost surely, 2^156904421 is an apocalyptic number.

It is an amenable number.

156904421 is a deficient number, since it is larger than the sum of its proper divisors (1).

156904421 is an equidigital number, since it uses as much as digits as its factorization.

156904421 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8640, while the sum is 32.

The square root of 156904421 is about 12526.1494881707. The cubic root of 156904421 is about 539.3595757094.

The spelling of 156904421 in words is "one hundred fifty-six million, nine hundred four thousand, four hundred twenty-one".