1221031009 has 4 divisors (see below), whose sum is σ = 1332033840. Its totient is φ = 1110028180.

The previous prime is 1221030997. The next prime is 1221031033. The reversal of 1221031009 is 9001301221.

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 1221031009 - 2¹⁵ = 1220998241 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1221031909) 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, 55501399 + ... + 55501420.

It is an arithmetic number, because the mean of its divisors is an integer number (333008460).

Almost surely, 2^1221031009 is an apocalyptic number.

It is an amenable number.

1221031009 is a deficient number, since it is larger than the sum of its proper divisors (111002831).

1221031009 is a wasteful number, since it uses less digits than its factorization.

1221031009 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 111002830.

The product of its (nonzero) digits is 108, while the sum is 19.

The square root of 1221031009 is about 34943.2541272275. The cubic root of 1221031009 is about 1068.8306464274.

The spelling of 1221031009 in words is "one billion, two hundred twenty-one million, thirty-one thousand, nine".