1206400505 has 4 divisors (see below), whose sum is σ = 1447680612. Its totient is φ = 965120400.

The previous prime is 1206400499. The next prime is 1206400511. The reversal of 1206400505 is 5050046021.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5050046021 = 27337 ⋅184733.

It is an interprime number because it is at equal distance from previous prime (1206400499) and next prime (1206400511).

It can be written as a sum of positive squares in 2 ways, for example, as 764854336 + 441546169 = 27656^2 + 21013^2 .

It is not a de Polignac number, because 1206400505 - 2¹² = 1206396409 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 120640046 + ... + 120640055.

It is an arithmetic number, because the mean of its divisors is an integer number (361920153).

Almost surely, 2^1206400505 is an apocalyptic number.

It is an amenable number.

1206400505 is a deficient number, since it is larger than the sum of its proper divisors (241280107).

1206400505 is an equidigital number, since it uses as much as digits as its factorization.

1206400505 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 241280106.

The product of its (nonzero) digits is 1200, while the sum is 23.

The square root of 1206400505 is about 34733.2766234342. The cubic root of 1206400505 is about 1064.5445399021.

Adding to 1206400505 its reverse (5050046021), we get a palindrome (6256446526).

The spelling of 1206400505 in words is "one billion, two hundred six million, four hundred thousand, five hundred five".