1340681621 has 4 divisors (see below), whose sum is σ = 1341475212. Its totient is φ = 1339888032.

The previous prime is 1340681609. The next prime is 1340681623. The reversal of 1340681621 is 1261860431.

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

It can be written as a sum of positive squares in 2 ways, for example, as 459244900 + 881436721 = 21430^2 + 29689^2 .

It is a cyclic number.

It is not a de Polignac number, because 1340681621 - 2¹⁰ = 1340680597 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1340681623) 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, 394256 + ... + 397641.

It is an arithmetic number, because the mean of its divisors is an integer number (335368803).

Almost surely, 2^1340681621 is an apocalyptic number.

It is an amenable number.

1340681621 is a deficient number, since it is larger than the sum of its proper divisors (793591).

1340681621 is an equidigital number, since it uses as much as digits as its factorization.

1340681621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 793590.

The product of its (nonzero) digits is 6912, while the sum is 32.

The square root of 1340681621 is about 36615.3194851554. The cubic root of 1340681621 is about 1102.6606724182.

The spelling of 1340681621 in words is "one billion, three hundred forty million, six hundred eighty-one thousand, six hundred twenty-one".