1220756417 has 4 divisors (see below), whose sum is σ = 1292565636. Its totient is φ = 1148947200.

The previous prime is 1220756393. The next prime is 1220756497. The reversal of 1220756417 is 7146570221.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 663371536 + 557384881 = 25756^2 + 23609^2 .

It is a cyclic number.

It is not a de Polignac number, because 1220756417 - 2¹⁴ = 1220740033 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1220756497) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 35904584 + ... + 35904617.

It is an arithmetic number, because the mean of its divisors is an integer number (323141409).

Almost surely, 2^1220756417 is an apocalyptic number.

1220756417 is a gapful number since it is divisible by the number (17) formed by its first and last digit.

It is an amenable number.

1220756417 is a deficient number, since it is larger than the sum of its proper divisors (71809219).

1220756417 is an equidigital number, since it uses as much as digits as its factorization.

1220756417 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 71809218.

The product of its (nonzero) digits is 23520, while the sum is 35.

The square root of 1220756417 is about 34939.3247931325. The cubic root of 1220756417 is about 1068.7505189651.

The spelling of 1220756417 in words is "one billion, two hundred twenty million, seven hundred fifty-six thousand, four hundred seventeen".