1221640735 has 16 divisors (see below), whose sum is σ = 1676505600. Its totient is φ = 837140256.

The previous prime is 1221640709. The next prime is 1221640759. The reversal of 1221640735 is 5370461221.

It is a cyclic number.

It is not a de Polignac number, because 1221640735 - 2⁵ = 1221640703 is a prime.

It is a super-2 number, since 2×1221640735² = 2984812170822680450, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1221640697 and 1221640706.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 45886 + ... + 67444.

It is an arithmetic number, because the mean of its divisors is an integer number (104781600).

Almost surely, 2^1221640735 is an apocalyptic number.

1221640735 is a deficient number, since it is larger than the sum of its proper divisors (454864865).

1221640735 is a wasteful number, since it uses less digits than its factorization.

1221640735 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23190.

The product of its (nonzero) digits is 10080, while the sum is 31.

The square root of 1221640735 is about 34951.9775549253. The cubic root of 1221640735 is about 1069.0085248992.

The spelling of 1221640735 in words is "one billion, two hundred twenty-one million, six hundred forty thousand, seven hundred thirty-five".