1228739261 has 2 divisors, whose sum is σ = 1228739262. Its totient is φ = 1228739260.

The previous prime is 1228739257. The next prime is 1228739269. The reversal of 1228739261 is 1629378221.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 625300036 + 603439225 = 25006^2 + 24565^2 .

It is a cyclic number.

It is not a de Polignac number, because 1228739261 - 2² = 1228739257 is a prime.

It is a super-2 number, since 2×1228739261² = 3019600343045652242, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1228739269) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 614369630 + 614369631.

It is an arithmetic number, because the mean of its divisors is an integer number (614369631).

Almost surely, 2^1228739261 is an apocalyptic number.

It is an amenable number.

1228739261 is a deficient number, since it is larger than the sum of its proper divisors (1).

1228739261 is an equidigital number, since it uses as much as digits as its factorization.

1228739261 is an evil number, because the sum of its binary digits is even.

The product of its digits is 72576, while the sum is 41.

The square root of 1228739261 is about 35053.3773123218. The cubic root of 1228739261 is about 1071.0750719727.

The spelling of 1228739261 in words is "one billion, two hundred twenty-eight million, seven hundred thirty-nine thousand, two hundred sixty-one".