155670821863 has 2 divisors, whose sum is σ = 155670821864. Its totient is φ = 155670821862.

The previous prime is 155670821861. The next prime is 155670821899. The reversal of 155670821863 is 368128076551.

It is a weak prime.

It is an emirp because it is prime and its reverse (368128076551) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 155670821863 - 2¹ = 155670821861 is a prime.

Together with 155670821861, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 155670821863.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (155670821861) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 77835410931 + 77835410932.

It is an arithmetic number, because the mean of its divisors is an integer number (77835410932).

Almost surely, 2^155670821863 is an apocalyptic number.

155670821863 is a deficient number, since it is larger than the sum of its proper divisors (1).

155670821863 is an equidigital number, since it uses as much as digits as its factorization.

155670821863 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2419200, while the sum is 52.

The spelling of 155670821863 in words is "one hundred fifty-five billion, six hundred seventy million, eight hundred twenty-one thousand, eight hundred sixty-three".