1021816139799 has 64 divisors (see below), whose sum is σ = 1750379079680. Its totient is φ = 515815672320.

The previous prime is 1021816139797. The next prime is 1021816139803. The reversal of 1021816139799 is 9979316181201.

It is a happy number.

It is not a de Polignac number, because 1021816139799 - 2¹ = 1021816139797 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1021816139797) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 213019 + ... + 1445340.

It is an arithmetic number, because the mean of its divisors is an integer number (27349673120).

Almost surely, 2^{1021816139799} is an apocalyptic number.

1021816139799 is a deficient number, since it is larger than the sum of its proper divisors (728562939881).

1021816139799 is a wasteful number, since it uses less digits than its factorization.

1021816139799 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1658480.

The product of its (nonzero) digits is 1469664, while the sum is 57.

The spelling of 1021816139799 in words is "one trillion, twenty-one billion, eight hundred sixteen million, one hundred thirty-nine thousand, seven hundred ninety-nine".