1009902393721 has 27 divisors (see below), whose sum is σ = 1143516619917. Its totient is φ = 891421090560.

The previous prime is 1009902393683. The next prime is 1009902393739. The reversal of 1009902393721 is 1273932099001.

It is a happy number.

The square root of 1009902393721 is 1004939.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 16619077225 + 993283316496 = 128915^2 + 996636^2 .

It is not a de Polignac number, because 1009902393721 - 2⁹ = 1009902393209 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1009902393751) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 300475081 + ... + 300478441.

Almost surely, 2^{1009902393721} is an apocalyptic number.

1009902393721 is the 1004939-th square number.

1009902393721 is the 502470-th centered octagonal number.

It is an amenable number.

1009902393721 is a deficient number, since it is larger than the sum of its proper divisors (133614226196).

1009902393721 is an frugal number, since it uses more digits than its factorization.

1009902393721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6794 (or 3397 counting only the distinct ones).

The product of its (nonzero) digits is 183708, while the sum is 46.

The spelling of 1009902393721 in words is "one trillion, nine billion, nine hundred two million, three hundred ninety-three thousand, seven hundred twenty-one".