155661621412387 has 2 divisors, whose sum is σ = 155661621412388. Its totient is φ = 155661621412386.

The previous prime is 155661621412337. The next prime is 155661621412489. The reversal of 155661621412387 is 783214126166551.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-155661621412387 is a prime.

It is a super-3 number, since 3×155661621412387³ (a number of 44 digits) contains 333 as substring.

It is not a weakly prime, because it can be changed into another prime (155661621412337) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 77830810706193 + 77830810706194.

It is an arithmetic number, because the mean of its divisors is an integer number (77830810706194).

Almost surely, 2^{155661621412387} is an apocalyptic number.

155661621412387 is a deficient number, since it is larger than the sum of its proper divisors (1).

155661621412387 is an equidigital number, since it uses as much as digits as its factorization.

155661621412387 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 14515200, while the sum is 58.

The spelling of 155661621412387 in words is "one hundred fifty-five trillion, six hundred sixty-one billion, six hundred twenty-one million, four hundred twelve thousand, three hundred eighty-seven".