1221204931 has 2 divisors, whose sum is σ = 1221204932. Its totient is φ = 1221204930.

The previous prime is 1221204893. The next prime is 1221204947. The reversal of 1221204931 is 1394021221.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1221204931 - 2¹⁵ = 1221172163 is a prime.

It is a super-2 number, since 2×1221204931² = 2982682966997429522, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1221204896 and 1221204905.

It is not a weakly prime, because it can be changed into another prime (1221204031) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610602465 + 610602466.

It is an arithmetic number, because the mean of its divisors is an integer number (610602466).

Almost surely, 2^1221204931 is an apocalyptic number.

1221204931 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221204931 is an equidigital number, since it uses as much as digits as its factorization.

1221204931 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 864, while the sum is 25.

The square root of 1221204931 is about 34945.7426734645. The cubic root of 1221204931 is about 1068.8813916137.

The spelling of 1221204931 in words is "one billion, two hundred twenty-one million, two hundred four thousand, nine hundred thirty-one".