1221880859 has 4 divisors (see below), whose sum is σ = 1254904704. Its totient is φ = 1188857016.

The previous prime is 1221880799. The next prime is 1221880871. The reversal of 1221880859 is 9580881221.

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

It is a cyclic number.

It is not a de Polignac number, because 1221880859 - 2¹⁶ = 1221815323 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1221880879) 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, 16511867 + ... + 16511940.

It is an arithmetic number, because the mean of its divisors is an integer number (313726176).

Almost surely, 2^1221880859 is an apocalyptic number.

1221880859 is a deficient number, since it is larger than the sum of its proper divisors (33023845).

1221880859 is an equidigital number, since it uses as much as digits as its factorization.

1221880859 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33023844.

The product of its (nonzero) digits is 92160, while the sum is 44.

The square root of 1221880859 is about 34955.4124421383. The cubic root of 1221880859 is about 1069.0785612525.

The spelling of 1221880859 in words is "one billion, two hundred twenty-one million, eight hundred eighty thousand, eight hundred fifty-nine".