1213697491 has 4 divisors (see below), whose sum is σ = 1220403184. Its totient is φ = 1206991800.

The previous prime is 1213697483. The next prime is 1213697519. The reversal of 1213697491 is 1947963121.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1213697491 - 2³ = 1213697483 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1213697411) 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, 3352575 + ... + 3352936.

It is an arithmetic number, because the mean of its divisors is an integer number (305100796).

Almost surely, 2^1213697491 is an apocalyptic number.

1213697491 is a deficient number, since it is larger than the sum of its proper divisors (6705693).

1213697491 is an equidigital number, since it uses as much as digits as its factorization.

1213697491 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6705692.

The product of its digits is 81648, while the sum is 43.

The square root of 1213697491 is about 34838.1614181920. The cubic root of 1213697491 is about 1066.6865475570.

The spelling of 1213697491 in words is "one billion, two hundred thirteen million, six hundred ninety-seven thousand, four hundred ninety-one".