1211201998 has 4 divisors (see below), whose sum is σ = 1816803000. Its totient is φ = 605600998.

The previous prime is 1211201989. The next prime is 1211202007. The reversal of 1211201998 is 8991021121.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 8991021121 = 479 ⋅18770399.

It is an interprime number because it is at equal distance from previous prime (1211201989) and next prime (1211202007).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 302800498 + ... + 302800501.

It is an arithmetic number, because the mean of its divisors is an integer number (454200750).

Almost surely, 2^1211201998 is an apocalyptic number.

1211201998 is a deficient number, since it is larger than the sum of its proper divisors (605601002).

1211201998 is an equidigital number, since it uses as much as digits as its factorization.

1211201998 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 605601001.

The product of its (nonzero) digits is 2592, while the sum is 34.

The square root of 1211201998 is about 34802.3274796385. The cubic root of 1211201998 is about 1065.9549717154.

The spelling of 1211201998 in words is "one billion, two hundred eleven million, two hundred one thousand, nine hundred ninety-eight".