1240651663 has 4 divisors (see below), whose sum is σ = 1259168920. Its totient is φ = 1222134408.

The previous prime is 1240651661. The next prime is 1240651667. The reversal of 1240651663 is 3661560421.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 3661560421 = 4519 ⋅810259.

It is a cyclic number.

It is not a de Polignac number, because 1240651663 - 2¹ = 1240651661 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1240651661) 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, 9258528 + ... + 9258661.

It is an arithmetic number, because the mean of its divisors is an integer number (314792230).

Almost surely, 2^1240651663 is an apocalyptic number.

1240651663 is a deficient number, since it is larger than the sum of its proper divisors (18517257).

1240651663 is an equidigital number, since it uses as much as digits as its factorization.

1240651663 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18517256.

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

The square root of 1240651663 is about 35222.8855007650. The cubic root of 1240651663 is about 1074.5252384920.

The spelling of 1240651663 in words is "one billion, two hundred forty million, six hundred fifty-one thousand, six hundred sixty-three".