1213267621 has 4 divisors (see below), whose sum is σ = 1213527744. Its totient is φ = 1213007500.

The previous prime is 1213267609. The next prime is 1213267631. The reversal of 1213267621 is 1267623121.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1267623121 = 14447 ⋅87743.

It is a cyclic number.

It is not a de Polignac number, because 1213267621 - 2⁵ = 1213267589 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 (1213267631) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 122935 + ... + 132436.

It is an arithmetic number, because the mean of its divisors is an integer number (303381936).

Almost surely, 2^1213267621 is an apocalyptic number.

It is an amenable number.

1213267621 is a deficient number, since it is larger than the sum of its proper divisors (260123).

1213267621 is an equidigital number, since it uses as much as digits as its factorization.

1213267621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 260122.

The product of its digits is 6048, while the sum is 31.

The square root of 1213267621 is about 34831.9913441652. The cubic root of 1213267621 is about 1066.5605989041.

The spelling of 1213267621 in words is "one billion, two hundred thirteen million, two hundred sixty-seven thousand, six hundred twenty-one".