155399819 has 4 divisors (see below), whose sum is σ = 155444544. Its totient is φ = 155355096.

The previous prime is 155399789. The next prime is 155399833. The reversal of 155399819 is 918993551.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 918993551 = 7 ⋅131284793.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-155399819 is a prime.

It is a super-2 number, since 2×155399819² = 48298207490465522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (155399899) 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 in 3 ways as a sum of consecutive naturals, for example, 16667 + ... + 24260.

It is an arithmetic number, because the mean of its divisors is an integer number (38861136).

Almost surely, 2^155399819 is an apocalyptic number.

155399819 is a deficient number, since it is larger than the sum of its proper divisors (44725).

155399819 is an equidigital number, since it uses as much as digits as its factorization.

155399819 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44724.

The product of its digits is 437400, while the sum is 50.

The square root of 155399819 is about 12465.9463740223. The cubic root of 155399819 is about 537.6300103029.

The spelling of 155399819 in words is "one hundred fifty-five million, three hundred ninety-nine thousand, eight hundred nineteen".