1221931 has 8 divisors (see below), whose sum is σ = 1265264. Its totient is φ = 1179360.

The previous prime is 1221917. The next prime is 1221937. The reversal of 1221931 is 1391221.

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 1221931 - 2¹⁵ = 1189163 is a prime.

It is a super-2 number, since 2×1221931² = 2986230737522, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1221899 and 1221908.

It is not an unprimeable number, because it can be changed into a prime (1221937) 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, 6661 + ... + 6841.

It is an arithmetic number, because the mean of its divisors is an integer number (158158).

2^1221931 is an apocalyptic number.

1221931 is a deficient number, since it is larger than the sum of its proper divisors (43333).

1221931 is a wasteful number, since it uses less digits than its factorization.

1221931 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 381.

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

The square root of 1221931 is about 1105.4098787328. The cubic root of 1221931 is about 106.9093184592.

The spelling of 1221931 in words is "one million, two hundred twenty-one thousand, nine hundred thirty-one".