1021938015817 has 4 divisors (see below), whose sum is σ = 1022893992580. Its totient is φ = 1020982039056.

The previous prime is 1021938015811. The next prime is 1021938015887. The reversal of 1021938015817 is 7185108391201.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 439225633081 + 582712382736 = 662741^2 + 763356^2 .

It is a cyclic number.

It is not a de Polignac number, because 1021938015817 - 2³ = 1021938015809 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1021938015811) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 477986778 + ... + 477988915.

It is an arithmetic number, because the mean of its divisors is an integer number (255723498145).

Almost surely, 2^{1021938015817} is an apocalyptic number.

It is an amenable number.

1021938015817 is a deficient number, since it is larger than the sum of its proper divisors (955976763).

1021938015817 is an equidigital number, since it uses as much as digits as its factorization.

1021938015817 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 955976762.

The product of its (nonzero) digits is 120960, while the sum is 46.

The spelling of 1021938015817 in words is "one trillion, twenty-one billion, nine hundred thirty-eight million, fifteen thousand, eight hundred seventeen".