1902890344721 has 4 divisors (see below), whose sum is σ = 1902898761252. Its totient is φ = 1902881928192.

The previous prime is 1902890344681. The next prime is 1902890344741. The reversal of 1902890344721 is 1274430982091.

It is a happy number.

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 831085666321 + 1071804678400 = 911639^2 + 1035280^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1902890344721 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1902890344721.

It is not an unprimeable number, because it can be changed into a prime (1902890344741) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3859496 + ... + 4324521.

It is an arithmetic number, because the mean of its divisors is an integer number (475724690313).

Almost surely, 2^{1902890344721} is an apocalyptic number.

It is an amenable number.

1902890344721 is a deficient number, since it is larger than the sum of its proper divisors (8416531).

1902890344721 is an equidigital number, since it uses as much as digits as its factorization.

1902890344721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8416530.

The product of its (nonzero) digits is 870912, while the sum is 50.

The spelling of 1902890344721 in words is "one trillion, nine hundred two billion, eight hundred ninety million, three hundred forty-four thousand, seven hundred twenty-one".