1220546891 has 2 divisors, whose sum is σ = 1220546892. Its totient is φ = 1220546890.

The previous prime is 1220546869. The next prime is 1220546927. The reversal of 1220546891 is 1986450221.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1220546891 is a prime.

It is not a weakly prime, because it can be changed into another prime (1220546191) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610273445 + 610273446.

It is an arithmetic number, because the mean of its divisors is an integer number (610273446).

Almost surely, 2^1220546891 is an apocalyptic number.

1220546891 is a deficient number, since it is larger than the sum of its proper divisors (1).

1220546891 is an equidigital number, since it uses as much as digits as its factorization.

1220546891 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 34560, while the sum is 38.

The square root of 1220546891 is about 34936.3262378860. The cubic root of 1220546891 is about 1068.6893700384.

The spelling of 1220546891 in words is "one billion, two hundred twenty million, five hundred forty-six thousand, eight hundred ninety-one".