1345721408 has 56 divisors (see below), whose sum is σ = 2777240064. Its totient is φ = 646272000.

The previous prime is 1345721389. The next prime is 1345721441. The reversal of 1345721408 is 8041275431.

It is a super-2 number, since 2×1345721408² = 3621932215899004928, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 269333 + ... + 274283.

Almost surely, 2^1345721408 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1345721408, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1388620032).

1345721408 is an abundant number, since it is smaller than the sum of its proper divisors (1431518656).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1345721408 is a wasteful number, since it uses less digits than its factorization.

1345721408 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5131 (or 5121 counting only the distinct ones).

The product of its (nonzero) digits is 26880, while the sum is 35.

The square root of 1345721408 is about 36684.0756732400. The cubic root of 1345721408 is about 1104.0406237239.

Adding to 1345721408 its reverse (8041275431), we get a palindrome (9386996839).

The spelling of 1345721408 in words is "one billion, three hundred forty-five million, seven hundred twenty-one thousand, four hundred eight".