1317290821 has 12 divisors (see below), whose sum is σ = 1654779616. Its totient is φ = 1026459720.

The previous prime is 1317290801. The next prime is 1317290827. The reversal of 1317290821 is 1280927131.

It is not a de Polignac number, because 1317290821 - 2²³ = 1308902213 is a prime.

It is a super-4 number, since 4×1317290821⁴ (a number of 38 digits) contains 4444 as substring.

It is a hoax number, since the sum of its digits (34) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1317290827) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 776775 + ... + 778468.

Almost surely, 2^1317290821 is an apocalyptic number.

1317290821 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1317290821 is a deficient number, since it is larger than the sum of its proper divisors (337488795).

1317290821 is a wasteful number, since it uses less digits than its factorization.

1317290821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1555272 (or 1555261 counting only the distinct ones).

The product of its (nonzero) digits is 6048, while the sum is 34.

The square root of 1317290821 is about 36294.5012501894. The cubic root of 1317290821 is about 1096.2103256311.

The spelling of 1317290821 in words is "one billion, three hundred seventeen million, two hundred ninety thousand, eight hundred twenty-one".