1221690073 has 4 divisors (see below), whose sum is σ = 1223458768. Its totient is φ = 1219921380.

The previous prime is 1221690061. The next prime is 1221690077. The reversal of 1221690073 is 3700961221.

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.

It is a cyclic number.

It is not a de Polignac number, because 1221690073 - 2²¹ = 1219592921 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1221690077) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 883311 + ... + 884692.

It is an arithmetic number, because the mean of its divisors is an integer number (305864692).

Almost surely, 2^1221690073 is an apocalyptic number.

It is an amenable number.

1221690073 is a deficient number, since it is larger than the sum of its proper divisors (1768695).

1221690073 is an equidigital number, since it uses as much as digits as its factorization.

1221690073 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1768694.

The product of its (nonzero) digits is 4536, while the sum is 31.

The square root of 1221690073 is about 34952.6833447734. The cubic root of 1221690073 is about 1069.0229159366.

The spelling of 1221690073 in words is "one billion, two hundred twenty-one million, six hundred ninety thousand, seventy-three".