1221121198 has 32 divisors (see below), whose sum is σ = 2090852352. Its totient is φ = 529452000.

The previous prime is 1221121193. The next prime is 1221121199. The reversal of 1221121198 is 8911211221.

It is a super-2 number, since 2×1221121198² = 2982273960409910408, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221121193) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 190648 + ... + 196948.

It is an arithmetic number, because the mean of its divisors is an integer number (65339136).

Almost surely, 2^1221121198 is an apocalyptic number.

1221121198 is a deficient number, since it is larger than the sum of its proper divisors (869731154).

1221121198 is a wasteful number, since it uses less digits than its factorization.

1221121198 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6720.

The product of its digits is 576, while the sum is 28.

The square root of 1221121198 is about 34944.5446099960. The cubic root of 1221121198 is about 1068.8569614549.

The spelling of 1221121198 in words is "one billion, two hundred twenty-one million, one hundred twenty-one thousand, one hundred ninety-eight".