1210991398 has 8 divisors (see below), whose sum is σ = 1846265760. Its totient is φ = 595569480.

The previous prime is 1210991387. The next prime is 1210991399. The reversal of 1210991398 is 8931990121.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1210991399) 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, 4962958 + ... + 4963201.

It is an arithmetic number, because the mean of its divisors is an integer number (230783220).

Almost surely, 2^1210991398 is an apocalyptic number.

1210991398 is a deficient number, since it is larger than the sum of its proper divisors (635274362).

1210991398 is an equidigital number, since it uses as much as digits as its factorization.

1210991398 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9926222.

The product of its (nonzero) digits is 34992, while the sum is 43.

The square root of 1210991398 is about 34799.3016883960. The cubic root of 1210991398 is about 1065.8931864999.

The spelling of 1210991398 in words is "one billion, two hundred ten million, nine hundred ninety-one thousand, three hundred ninety-eight".