1221385747 has 2 divisors, whose sum is σ = 1221385748. Its totient is φ = 1221385746.

The previous prime is 1221385733. The next prime is 1221385769. The reversal of 1221385747 is 7475831221.

It is a weak prime.

It is an emirp because it is prime and its reverse (7475831221) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1221385747 - 2¹¹ = 1221383699 is a prime.

It is not a weakly prime, because it can be changed into another prime (1221385787) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610692873 + 610692874.

It is an arithmetic number, because the mean of its divisors is an integer number (610692874).

Almost surely, 2^1221385747 is an apocalyptic number.

1221385747 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221385747 is an equidigital number, since it uses as much as digits as its factorization.

1221385747 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 94080, while the sum is 40.

The square root of 1221385747 is about 34948.3296739630. The cubic root of 1221385747 is about 1068.9341431530.

The spelling of 1221385747 in words is "one billion, two hundred twenty-one million, three hundred eighty-five thousand, seven hundred forty-seven".