55861381 has 4 divisors (see below), whose sum is σ = 55889932. Its totient is φ = 55832832.

The previous prime is 55861367. The next prime is 55861391. The reversal of 55861381 is 18316855.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 17297281 + 38564100 = 4159^2 + 6210^2 .

It is a cyclic number.

It is not a de Polignac number, because 55861381 - 2¹⁷ = 55730309 is a prime.

It is a super-2 number, since 2×55861381² = 6240987774454322, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 55861381.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55861321) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11106 + ... + 15331.

It is an arithmetic number, because the mean of its divisors is an integer number (13972483).

Almost surely, 2^55861381 is an apocalyptic number.

It is an amenable number.

55861381 is a deficient number, since it is larger than the sum of its proper divisors (28551).

55861381 is a wasteful number, since it uses less digits than its factorization.

55861381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28550.

The product of its digits is 28800, while the sum is 37.

The square root of 55861381 is about 7474.0471633513. The cubic root of 55861381 is about 382.2702988127.

The spelling of 55861381 in words is "fifty-five million, eight hundred sixty-one thousand, three hundred eighty-one".