55142621 has 2 divisors, whose sum is σ = 55142622. Its totient is φ = 55142620.

The previous prime is 55142599. The next prime is 55142629. The reversal of 55142621 is 12624155.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 53728900 + 1413721 = 7330^2 + 1189^2 .

It is a cyclic number.

It is not a de Polignac number, because 55142621 - 2¹⁸ = 54880477 is a prime.

It is a Sophie Germain prime.

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 (55142629) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27571310 + 27571311.

It is an arithmetic number, because the mean of its divisors is an integer number (27571311).

Almost surely, 2^55142621 is an apocalyptic number.

It is an amenable number.

55142621 is a deficient number, since it is larger than the sum of its proper divisors (1).

55142621 is an equidigital number, since it uses as much as digits as its factorization.

55142621 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2400, while the sum is 26.

The square root of 55142621 is about 7425.8077675092. The cubic root of 55142621 is about 380.6236780395.

Adding to 55142621 its reverse (12624155), we get a palindrome (67766776).

The spelling of 55142621 in words is "fifty-five million, one hundred forty-two thousand, six hundred twenty-one".