1055665421 has 2 divisors, whose sum is σ = 1055665422. Its totient is φ = 1055665420.

The previous prime is 1055665411. The next prime is 1055665423. The reversal of 1055665421 is 1245665501.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 984076900 + 71588521 = 31370^2 + 8461^2 .

It is an emirp because it is prime and its reverse (1245665501) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1055665421 - 2¹⁰ = 1055664397 is a prime.

It is a super-2 number, since 2×1055665421² = 2228858962190214482, which contains 22 as substring.

Together with 1055665423, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1055665423) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 527832710 + 527832711.

It is an arithmetic number, because the mean of its divisors is an integer number (527832711).

Almost surely, 2^1055665421 is an apocalyptic number.

It is an amenable number.

1055665421 is a deficient number, since it is larger than the sum of its proper divisors (1).

1055665421 is an equidigital number, since it uses as much as digits as its factorization.

1055665421 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 36000, while the sum is 35.

The square root of 1055665421 is about 32491.0052322177. The cubic root of 1055665421 is about 1018.2211147845.

The spelling of 1055665421 in words is "one billion, fifty-five million, six hundred sixty-five thousand, four hundred twenty-one".