55897421 has 2 divisors, whose sum is σ = 55897422. Its totient is φ = 55897420.

The previous prime is 55897381. The next prime is 55897423. The reversal of 55897421 is 12479855.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 47803396 + 8094025 = 6914^2 + 2845^2 .

It is a cyclic number.

It is not a de Polignac number, because 55897421 - 2¹⁸ = 55635277 is a prime.

It is a Sophie Germain prime.

Together with 55897423, it forms a pair of twin primes.

It is a Chen 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 (55897423) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27948710 + 27948711.

It is an arithmetic number, because the mean of its divisors is an integer number (27948711).

Almost surely, 2^55897421 is an apocalyptic number.

It is an amenable number.

55897421 is a deficient number, since it is larger than the sum of its proper divisors (1).

55897421 is an equidigital number, since it uses as much as digits as its factorization.

55897421 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 100800, while the sum is 41.

The square root of 55897421 is about 7476.4577842719. The cubic root of 55897421 is about 382.3524907167.

It can be divided in two parts, 558 and 97421, that added together give a palindrome (97979).

The spelling of 55897421 in words is "fifty-five million, eight hundred ninety-seven thousand, four hundred twenty-one".