55896781 has 2 divisors, whose sum is σ = 55896782. Its totient is φ = 55896780.

The previous prime is 55896779. The next prime is 55896787. The reversal of 55896781 is 18769855.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 55636681 + 260100 = 7459^2 + 510^2 .

It is a cyclic number.

It is not a de Polignac number, because 55896781 - 2¹ = 55896779 is a prime.

It is a super-2 number, since 2×55896781² = 6248900252323922, which contains 22 as substring.

Together with 55896779, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (55896787) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27948390 + 27948391.

It is an arithmetic number, because the mean of its divisors is an integer number (27948391).

Almost surely, 2^55896781 is an apocalyptic number.

55896781 is the 4729-th centered pentagonal number.

It is an amenable number.

55896781 is a deficient number, since it is larger than the sum of its proper divisors (1).

55896781 is an equidigital number, since it uses as much as digits as its factorization.

55896781 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 604800, while the sum is 49.

The square root of 55896781 is about 7476.4149831320. The cubic root of 55896781 is about 382.3510314572.

The spelling of 55896781 in words is "fifty-five million, eight hundred ninety-six thousand, seven hundred eighty-one".