1220839261 has 2 divisors, whose sum is σ = 1220839262. Its totient is φ = 1220839260.

The previous prime is 1220839253. The next prime is 1220839267. The reversal of 1220839261 is 1629380221.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 784280025 + 436559236 = 28005^2 + 20894^2 .

It is a cyclic number.

It is not a de Polignac number, because 1220839261 - 2³ = 1220839253 is a prime.

It is a super-2 number, since 2×1220839261² = 2980897002398052242, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1220839267) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610419630 + 610419631.

It is an arithmetic number, because the mean of its divisors is an integer number (610419631).

Almost surely, 2^1220839261 is an apocalyptic number.

It is an amenable number.

1220839261 is a deficient number, since it is larger than the sum of its proper divisors (1).

1220839261 is an equidigital number, since it uses as much as digits as its factorization.

1220839261 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 10368, while the sum is 34.

The square root of 1220839261 is about 34940.5103139608. The cubic root of 1220839261 is about 1068.7746945675.

The spelling of 1220839261 in words is "one billion, two hundred twenty million, eight hundred thirty-nine thousand, two hundred sixty-one".