155393939 has 2 divisors, whose sum is σ = 155393940. Its totient is φ = 155393938.

The previous prime is 155393929. The next prime is 155393941. The reversal of 155393939 is 939393551.

155393939 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 155393939 - 2⁸ = 155393683 is a prime.

It is a Sophie Germain prime.

Together with 155393941, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 155393893 and 155393902.

It is not a weakly prime, because it can be changed into another prime (155393929) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 77696969 + 77696970.

It is an arithmetic number, because the mean of its divisors is an integer number (77696970).

Almost surely, 2^155393939 is an apocalyptic number.

155393939 is a deficient number, since it is larger than the sum of its proper divisors (1).

155393939 is an equidigital number, since it uses as much as digits as its factorization.

155393939 is an evil number, because the sum of its binary digits is even.

The product of its digits is 492075, while the sum is 47.

The square root of 155393939 is about 12465.7105292879. The cubic root of 155393939 is about 537.6232292904.

The spelling of 155393939 in words is "one hundred fifty-five million, three hundred ninety-three thousand, nine hundred thirty-nine".