1221367898 has 4 divisors (see below), whose sum is σ = 1832051850. Its totient is φ = 610683948.

The previous prime is 1221367831. The next prime is 1221367913. The reversal of 1221367898 is 8987631221.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 8987631221 = 467 ⋅19245463.

It can be written as a sum of positive squares in only one way, i.e., 662187289 + 559180609 = 25733^2 + 23647^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 305341973 + ... + 305341976.

Almost surely, 2^1221367898 is an apocalyptic number.

1221367898 is a deficient number, since it is larger than the sum of its proper divisors (610683952).

1221367898 is an equidigital number, since it uses as much as digits as its factorization.

1221367898 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 610683951.

The product of its digits is 290304, while the sum is 47.

The square root of 1221367898 is about 34948.0743103250. The cubic root of 1221367898 is about 1068.9289360898.

The spelling of 1221367898 in words is "one billion, two hundred twenty-one million, three hundred sixty-seven thousand, eight hundred ninety-eight".