54897781 has 4 divisors (see below), whose sum is σ = 55514700. Its totient is φ = 54280864.

The previous prime is 54897761. The next prime is 54897797. The reversal of 54897781 is 18779845.

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 18404100 + 36493681 = 4290^2 + 6041^2 .

It is a cyclic number.

It is not a de Polignac number, because 54897781 - 2⁵ = 54897749 is a prime.

It is a super-2 number, since 2×54897781² = 6027532717447922, which contains 22 as substring.

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (54897701) 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, 308326 + ... + 308503.

It is an arithmetic number, because the mean of its divisors is an integer number (13878675).

Almost surely, 2^54897781 is an apocalyptic number.

It is an amenable number.

54897781 is a deficient number, since it is larger than the sum of its proper divisors (616919).

54897781 is an equidigital number, since it uses as much as digits as its factorization.

54897781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 616918.

The product of its digits is 564480, while the sum is 49.

The square root of 54897781 is about 7409.3036784842. The cubic root of 54897781 is about 380.0595036090.

The spelling of 54897781 in words is "fifty-four million, eight hundred ninety-seven thousand, seven hundred eighty-one".