1243626661 has 8 divisors (see below), whose sum is σ = 1249920000. Its totient is φ = 1237349952.

The previous prime is 1243626649. The next prime is 1243626677. The reversal of 1243626661 is 1666263421.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1243626661 - 2¹³ = 1243618469 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 1243626661.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1243626161) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 162090 + ... + 169588.

It is an arithmetic number, because the mean of its divisors is an integer number (156240000).

Almost surely, 2^1243626661 is an apocalyptic number.

It is an amenable number.

1243626661 is a deficient number, since it is larger than the sum of its proper divisors (6293339).

1243626661 is an equidigital number, since it uses as much as digits as its factorization.

1243626661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8315.

The product of its digits is 62208, while the sum is 37.

The square root of 1243626661 is about 35265.0912518315. The cubic root of 1243626661 is about 1075.3834322850.

The spelling of 1243626661 in words is "one billion, two hundred forty-three million, six hundred twenty-six thousand, six hundred sixty-one".