53778821 has 2 divisors, whose sum is σ = 53778822. Its totient is φ = 53778820.

The previous prime is 53778799. The next prime is 53778863. The reversal of 53778821 is 12887735.

53778821 = 5185² + 5186².

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 26894596 + 26884225 = 5186^2 + 5185^2 .

It is a cyclic number.

It is not a de Polignac number, because 53778821 - 2¹⁰ = 53777797 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (53778121) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 26889410 + 26889411.

It is an arithmetic number, because the mean of its divisors is an integer number (26889411).

Almost surely, 2^53778821 is an apocalyptic number.

53778821 is the 5186-th centered square number.

It is an amenable number.

53778821 is a deficient number, since it is larger than the sum of its proper divisors (1).

53778821 is an equidigital number, since it uses as much as digits as its factorization.

53778821 is an evil number, because the sum of its binary digits is even.

The product of its digits is 94080, while the sum is 41.

The square root of 53778821 is about 7333.4044617763. The cubic root of 53778821 is about 377.4595567977.

The spelling of 53778821 in words is "fifty-three million, seven hundred seventy-eight thousand, eight hundred twenty-one".