55151721556 has 6 divisors (see below), whose sum is σ = 96515512730. Its totient is φ = 27575860776.

The previous prime is 55151721533. The next prime is 55151721557. The reversal of 55151721556 is 65512715155.

It can be written as a sum of positive squares in only one way, i.e., 38021100100 + 17130621456 = 194990^2 + 130884^2 .

It is a super-2 number, since 2×55151721556² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55151721557) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6893965191 + ... + 6893965198.

Almost surely, 2^55151721556 is an apocalyptic number.

It is an amenable number.

55151721556 is a deficient number, since it is larger than the sum of its proper divisors (41363791174).

55151721556 is a wasteful number, since it uses less digits than its factorization.

55151721556 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13787930393 (or 13787930391 counting only the distinct ones).

The product of its digits is 262500, while the sum is 43.

The spelling of 55151721556 in words is "fifty-five billion, one hundred fifty-one million, seven hundred twenty-one thousand, five hundred fifty-six".