1021020551 has 2 divisors, whose sum is σ = 1021020552. Its totient is φ = 1021020550.

The previous prime is 1021020529. The next prime is 1021020589. The reversal of 1021020551 is 1550201201.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1021020551 - 2¹⁸ = 1020758407 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1021020751) 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, 510510275 + 510510276.

It is an arithmetic number, because the mean of its divisors is an integer number (510510276).

Almost surely, 2^1021020551 is an apocalyptic number.

1021020551 is a deficient number, since it is larger than the sum of its proper divisors (1).

1021020551 is an equidigital number, since it uses as much as digits as its factorization.

1021020551 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 100, while the sum is 17.

The square root of 1021020551 is about 31953.4121965088. The cubic root of 1021020551 is about 1006.9583198155.

Adding to 1021020551 its reverse (1550201201), we get a palindrome (2571221752).

The spelling of 1021020551 in words is "one billion, twenty-one million, twenty thousand, five hundred fifty-one".