1313121491 has 4 divisors (see below), whose sum is σ = 1432496184. Its totient is φ = 1193746800.

The previous prime is 1313121461. The next prime is 1313121493. The reversal of 1313121491 is 1941213131.

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 1313121491 - 2¹⁸ = 1312859347 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1313121491.

It is not an unprimeable number, because it can be changed into a prime (1313121493) 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, 59687330 + ... + 59687351.

It is an arithmetic number, because the mean of its divisors is an integer number (358124046).

Almost surely, 2^1313121491 is an apocalyptic number.

1313121491 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

1313121491 is a deficient number, since it is larger than the sum of its proper divisors (119374693).

1313121491 is a wasteful number, since it uses less digits than its factorization.

1313121491 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 119374692.

The product of its digits is 648, while the sum is 26.

The square root of 1313121491 is about 36237.0182410198. The cubic root of 1313121491 is about 1095.0525724152.

The spelling of 1313121491 in words is "one billion, three hundred thirteen million, one hundred twenty-one thousand, four hundred ninety-one".