55021507 has 2 divisors, whose sum is σ = 55021508. Its totient is φ = 55021506.

The previous prime is 55021489. The next prime is 55021513. The reversal of 55021507 is 70512055.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-55021507 is a prime.

It is not a weakly prime, because it can be changed into another prime (55021907) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27510753 + 27510754.

It is an arithmetic number, because the mean of its divisors is an integer number (27510754).

Almost surely, 2^55021507 is an apocalyptic number.

55021507 is a deficient number, since it is larger than the sum of its proper divisors (1).

55021507 is an equidigital number, since it uses as much as digits as its factorization.

55021507 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1750, while the sum is 25.

The square root of 55021507 is about 7417.6483470167. The cubic root of 55021507 is about 380.3448093731.

The spelling of 55021507 in words is "fifty-five million, twenty-one thousand, five hundred seven".