55087421 has 2 divisors, whose sum is σ = 55087422. Its totient is φ = 55087420.

The previous prime is 55087399. The next prime is 55087423. The reversal of 55087421 is 12478055.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 52562500 + 2524921 = 7250^2 + 1589^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-55087421 is a prime.

It is a Sophie Germain prime.

Together with 55087423, 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 (55087423) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27543710 + 27543711.

It is an arithmetic number, because the mean of its divisors is an integer number (27543711).

Almost surely, 2^55087421 is an apocalyptic number.

It is an amenable number.

55087421 is a deficient number, since it is larger than the sum of its proper divisors (1).

55087421 is an equidigital number, since it uses as much as digits as its factorization.

55087421 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 11200, while the sum is 32.

The square root of 55087421 is about 7422.0900695155. The cubic root of 55087421 is about 380.4966290569.

The spelling of 55087421 in words is "fifty-five million, eighty-seven thousand, four hundred twenty-one".