155566665551 has 8 divisors (see below), whose sum is σ = 169778643408. Its totient is φ = 141366280000.

The previous prime is 155566665521. The next prime is 155566665563.

155566665551 is nontrivially palindromic in base 10.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 155566665551 - 2⁶ = 155566665487 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (155566665521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2870000 + ... + 2923701.

It is an arithmetic number, because the mean of its divisors is an integer number (21222330426).

Almost surely, 2^155566665551 is an apocalyptic number.

155566665551 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

155566665551 is a deficient number, since it is larger than the sum of its proper divisors (14211977857).

155566665551 is a wasteful number, since it uses less digits than its factorization.

155566665551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5796153.

The product of its digits is 20250000, while the sum is 56.

The spelling of 155566665551 in words is "one hundred fifty-five billion, five hundred sixty-six million, six hundred sixty-five thousand, five hundred fifty-one".