1213136491 has 8 divisors (see below), whose sum is σ = 1459412480. Its totient is φ = 985103208.

The previous prime is 1213136471. The next prime is 1213136503. The reversal of 1213136491 is 1946313121.

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

It is a cyclic number.

It is not a de Polignac number, because 1213136491 - 2¹¹ = 1213134443 is a prime.

It is a super-4 number, since 4×1213136491⁴ (a number of 37 digits) contains 4444 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1213136471) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4560531 + ... + 4560796.

It is an arithmetic number, because the mean of its divisors is an integer number (182426560).

Almost surely, 2^1213136491 is an apocalyptic number.

1213136491 is a deficient number, since it is larger than the sum of its proper divisors (246275989).

1213136491 is an equidigital number, since it uses as much as digits as its factorization.

1213136491 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9121353.

The product of its digits is 3888, while the sum is 31.

The square root of 1213136491 is about 34830.1089719800. The cubic root of 1213136491 is about 1066.5221728861.

The spelling of 1213136491 in words is "one billion, two hundred thirteen million, one hundred thirty-six thousand, four hundred ninety-one".