55779864 has 64 divisors (see below), whose sum is σ = 162013440. Its totient is φ = 15672960.

The previous prime is 55779863. The next prime is 55779887. The reversal of 55779864 is 46897755.

It is a super-2 number, since 2×55779864² = 6222786455716992, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55779863) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7527 + ... + 12969.

It is an arithmetic number, because the mean of its divisors is an integer number (2531460).

Almost surely, 2^55779864 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 55779864, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (81006720).

55779864 is an abundant number, since it is smaller than the sum of its proper divisors (106233576).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

55779864 is a wasteful number, since it uses less digits than its factorization.

55779864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5520 (or 5516 counting only the distinct ones).

The product of its digits is 2116800, while the sum is 51.

The square root of 55779864 is about 7468.5918351454. The cubic root of 55779864 is about 382.0842627271.

The spelling of 55779864 in words is "fifty-five million, seven hundred seventy-nine thousand, eight hundred sixty-four".