155402317781 has 4 divisors (see below), whose sum is σ = 155448585600. Its totient is φ = 155356049964.

The previous prime is 155402317757. The next prime is 155402317823. The reversal of 155402317781 is 187713204551.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-155402317781 is a prime.

It is a super-2 number, since 2×155402317781² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (155402317981) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 23128871 + ... + 23135588.

It is an arithmetic number, because the mean of its divisors is an integer number (38862146400).

Almost surely, 2^155402317781 is an apocalyptic number.

It is an amenable number.

155402317781 is a deficient number, since it is larger than the sum of its proper divisors (46267819).

155402317781 is an equidigital number, since it uses as much as digits as its factorization.

155402317781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 46267818.

The product of its (nonzero) digits is 235200, while the sum is 44.

The spelling of 155402317781 in words is "one hundred fifty-five billion, four hundred two million, three hundred seventeen thousand, seven hundred eighty-one".