1290640543 has 4 divisors (see below), whose sum is σ = 1290921408. Its totient is φ = 1290359680.

The previous prime is 1290640537. The next prime is 1290640553. The reversal of 1290640543 is 3450460921.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1290640543 is a prime.

It is a super-2 number, since 2×1290640543² = 3331506022470669698, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1290640499 and 1290640508.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1290640513) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 133423 + ... + 142768.

It is an arithmetic number, because the mean of its divisors is an integer number (322730352).

Almost surely, 2^1290640543 is an apocalyptic number.

1290640543 is a deficient number, since it is larger than the sum of its proper divisors (280865).

1290640543 is an equidigital number, since it uses as much as digits as its factorization.

1290640543 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 280864.

The product of its (nonzero) digits is 25920, while the sum is 34.

The square root of 1290640543 is about 35925.4859814032. The cubic root of 1290640543 is about 1088.7673811410.

The spelling of 1290640543 in words is "one billion, two hundred ninety million, six hundred forty thousand, five hundred forty-three".