55783816815 has 32 divisors (see below), whose sum is σ = 90727854336. Its totient is φ = 29263887360.

The previous prime is 55783816807. The next prime is 55783816817. The reversal of 55783816815 is 51861838755.

It is not a de Polignac number, because 55783816815 - 2³ = 55783816807 is a prime.

It is a super-2 number, since 2×55783816815² (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 (55783816817) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 119560 + ... + 354770.

It is an arithmetic number, because the mean of its divisors is an integer number (2835245448).

Almost surely, 2^55783816815 is an apocalyptic number.

55783816815 is a deficient number, since it is larger than the sum of its proper divisors (34944037521).

55783816815 is a wasteful number, since it uses less digits than its factorization.

55783816815 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 235479.

The product of its digits is 8064000, while the sum is 57.

The spelling of 55783816815 in words is "fifty-five billion, seven hundred eighty-three million, eight hundred sixteen thousand, eight hundred fifteen".