155463991 has 2 divisors, whose sum is σ = 155463992. Its totient is φ = 155463990.

The previous prime is 155463989. The next prime is 155464007. The reversal of 155463991 is 199364551.

It is a weak prime.

It is an emirp because it is prime and its reverse (199364551) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 155463991 - 2¹ = 155463989 is a prime.

Together with 155463989, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (155463911) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 77731995 + 77731996.

It is an arithmetic number, because the mean of its divisors is an integer number (77731996).

Almost surely, 2^155463991 is an apocalyptic number.

155463991 is a deficient number, since it is larger than the sum of its proper divisors (1).

155463991 is an equidigital number, since it uses as much as digits as its factorization.

155463991 is an evil number, because the sum of its binary digits is even.

The product of its digits is 145800, while the sum is 43.

The square root of 155463991 is about 12468.5200003850. The cubic root of 155463991 is about 537.7040044798.

The spelling of 155463991 in words is "one hundred fifty-five million, four hundred sixty-three thousand, nine hundred ninety-one".