55390409 has 2 divisors, whose sum is σ = 55390410. Its totient is φ = 55390408.

The previous prime is 55390381. The next prime is 55390411. The reversal of 55390409 is 90409355.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 33674809 + 21715600 = 5803^2 + 4660^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-55390409 is a prime.

Together with 55390411, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (55390499) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27695204 + 27695205.

It is an arithmetic number, because the mean of its divisors is an integer number (27695205).

Almost surely, 2^55390409 is an apocalyptic number.

It is an amenable number.

55390409 is a deficient number, since it is larger than the sum of its proper divisors (1).

55390409 is an equidigital number, since it uses as much as digits as its factorization.

55390409 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 24300, while the sum is 35.

The square root of 55390409 is about 7442.4733120113. The cubic root of 55390409 is about 381.1929476932.

The spelling of 55390409 in words is "fifty-five million, three hundred ninety thousand, four hundred nine".