2021515535551 has 2 divisors, whose sum is σ = 2021515535552. Its totient is φ = 2021515535550.

The previous prime is 2021515535549. The next prime is 2021515535579. The reversal of 2021515535551 is 1555355151202.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 2021515535551 - 2¹ = 2021515535549 is a prime.

Together with 2021515535549, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2021515535581) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1010757767775 + 1010757767776.

It is an arithmetic number, because the mean of its divisors is an integer number (1010757767776).

Almost surely, 2^{2021515535551} is an apocalyptic number.

2021515535551 is a deficient number, since it is larger than the sum of its proper divisors (1).

2021515535551 is an equidigital number, since it uses as much as digits as its factorization.

2021515535551 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 187500, while the sum is 40.

The spelling of 2021515535551 in words is "two trillion, twenty-one billion, five hundred fifteen million, five hundred thirty-five thousand, five hundred fifty-one".