55423781 has 8 divisors (see below), whose sum is σ = 63426240. Its totient is φ = 47442528.

The previous prime is 55423777. The next prime is 55423787. The reversal of 55423781 is 18732455.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 55423781 - 2² = 55423777 is a prime.

It is a super-2 number, since 2×55423781² = 6143591000671922, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55423787) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 770 + ... + 10556.

It is an arithmetic number, because the mean of its divisors is an integer number (7928280).

Almost surely, 2^55423781 is an apocalyptic number.

It is an amenable number.

55423781 is a deficient number, since it is larger than the sum of its proper divisors (8002459).

55423781 is an equidigital number, since it uses as much as digits as its factorization.

55423781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10603.

The product of its digits is 33600, while the sum is 35.

The square root of 55423781 is about 7444.7149710382. The cubic root of 55423781 is about 381.2694869194.

The spelling of 55423781 in words is "fifty-five million, four hundred twenty-three thousand, seven hundred eighty-one".