1316923921 has 16 divisors (see below), whose sum is σ = 1410189264. Its totient is φ = 1225498624.

The previous prime is 1316923873. The next prime is 1316923961. The reversal of 1316923921 is 1293296131.

It can be written as a sum of positive squares in 8 ways, for example, as 850363921 + 466560000 = 29161^2 + 21600^2 .

It is a cyclic number.

It is not a de Polignac number, because 1316923921 - 2¹¹ = 1316921873 is a prime.

It is a super-2 number, since 2×1316923921² = 3468577227404028482, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1316923961) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 578241 + ... + 580513.

It is an arithmetic number, because the mean of its divisors is an integer number (88136829).

Almost surely, 2^1316923921 is an apocalyptic number.

It is an amenable number.

1316923921 is a deficient number, since it is larger than the sum of its proper divisors (93265343).

1316923921 is a wasteful number, since it uses less digits than its factorization.

1316923921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2660.

The product of its digits is 17496, while the sum is 37.

The square root of 1316923921 is about 36289.4464135236. The cubic root of 1316923921 is about 1096.1085417504.

The spelling of 1316923921 in words is "one billion, three hundred sixteen million, nine hundred twenty-three thousand, nine hundred twenty-one".