156739421 has 2 divisors, whose sum is σ = 156739422. Its totient is φ = 156739420.

The previous prime is 156739409. The next prime is 156739447. The reversal of 156739421 is 124937651.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 143880025 + 12859396 = 11995^2 + 3586^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-156739421 is a prime.

It is a Chen prime.

It is equal to p_8801867 and since 156739421 and 8801867 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (156739481) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 78369710 + 78369711.

It is an arithmetic number, because the mean of its divisors is an integer number (78369711).

Almost surely, 2^156739421 is an apocalyptic number.

It is an amenable number.

156739421 is a deficient number, since it is larger than the sum of its proper divisors (1).

156739421 is an equidigital number, since it uses as much as digits as its factorization.

156739421 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 45360, while the sum is 38.

The square root of 156739421 is about 12519.5615338557. The cubic root of 156739421 is about 539.1704466778.

The spelling of 156739421 in words is "one hundred fifty-six million, seven hundred thirty-nine thousand, four hundred twenty-one".