1400205989809 has 27 divisors (see below), whose sum is σ = 1556503181121. Its totient is φ = 1258655735040.

The previous prime is 1400205989807. The next prime is 1400205989837. The reversal of 1400205989809 is 9089895020041.

The square root of 1400205989809 is 1183303.

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 593493048225 + 806712941584 = 770385^2 + 898172^2 .

It is not a de Polignac number, because 1400205989809 - 2¹ = 1400205989807 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 1400205989809.

It is not an unprimeable number, because it can be changed into a prime (1400205989801) 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, 1262583747 + ... + 1262584855.

Almost surely, 2^{1400205989809} is an apocalyptic number.

1400205989809 is the 1183303-rd square number.

1400205989809 is the 591652-nd centered octagonal number.

It is an amenable number.

1400205989809 is a deficient number, since it is larger than the sum of its proper divisors (156297191312).

1400205989809 is an frugal number, since it uses more digits than its factorization.

1400205989809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2434 (or 1217 counting only the distinct ones).

The product of its (nonzero) digits is 1866240, while the sum is 55.

The spelling of 1400205989809 in words is "one trillion, four hundred billion, two hundred five million, nine hundred eighty-nine thousand, eight hundred nine".