1021552215551 has 12 divisors (see below), whose sum is σ = 1188357701040. Its totient is φ = 875600379360.

The previous prime is 1021552215547. The next prime is 1021552215631. The reversal of 1021552215551 is 1555122551201.

It is not a de Polignac number, because 1021552215551 - 2² = 1021552215547 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1021552215521) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3153635 + ... + 3462443.

It is an arithmetic number, because the mean of its divisors is an integer number (99029808420).

Almost surely, 2^{1021552215551} is an apocalyptic number.

1021552215551 is a deficient number, since it is larger than the sum of its proper divisors (166805485489).

1021552215551 is an equidigital number, since it uses as much as digits as its factorization.

1021552215551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 376334 (or 376327 counting only the distinct ones).

The product of its (nonzero) digits is 25000, while the sum is 35.

Adding to 1021552215551 its reverse (1555122551201), we get a palindrome (2576674766752).

The spelling of 1021552215551 in words is "one trillion, twenty-one billion, five hundred fifty-two million, two hundred fifteen thousand, five hundred fifty-one".