1221804858 has 64 divisors (see below), whose sum is σ = 2687074560. Its totient is φ = 368643072.

The previous prime is 1221804851. The next prime is 1221804889. The reversal of 1221804858 is 8584081221.

It is a super-2 number, since 2×1221804858² = 2985614222064800328, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1221804851) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 937035 + ... + 938337.

It is an arithmetic number, because the mean of its divisors is an integer number (41985540).

Almost surely, 2^1221804858 is an apocalyptic number.

1221804858 is an abundant number, since it is smaller than the sum of its proper divisors (1465269702).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1221804858 is a wasteful number, since it uses less digits than its factorization.

1221804858 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1671.

The product of its (nonzero) digits is 40960, while the sum is 39.

The square root of 1221804858 is about 34954.3253117551. The cubic root of 1221804858 is about 1069.0563952276.

The spelling of 1221804858 in words is "one billion, two hundred twenty-one million, eight hundred four thousand, eight hundred fifty-eight".