1290541665 has 24 divisors (see below), whose sum is σ = 2401989120. Its totient is φ = 589961568.

The previous prime is 1290541663. The next prime is 1290541667. The reversal of 1290541665 is 5661450921.

It is an interprime number because it is at equal distance from previous prime (1290541663) and next prime (1290541667).

It is not a de Polignac number, because 1290541665 - 2¹ = 1290541663 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1290541663) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 877185 + ... + 878654.

It is an arithmetic number, because the mean of its divisors is an integer number (100082880).

Almost surely, 2^1290541665 is an apocalyptic number.

1290541665 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1290541665 is a deficient number, since it is larger than the sum of its proper divisors (1111447455).

1290541665 is a wasteful number, since it uses less digits than its factorization.

1290541665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1755861 (or 1755854 counting only the distinct ones).

The product of its (nonzero) digits is 64800, while the sum is 39.

The square root of 1290541665 is about 35924.1098010793. The cubic root of 1290541665 is about 1088.7395763709.

The spelling of 1290541665 in words is "one billion, two hundred ninety million, five hundred forty-one thousand, six hundred sixty-five".