6407535378721 has 27 divisors (see below), whose sum is σ = 6750802313913. Its totient is φ = 6081221546400.

The previous prime is 6407535378707. The next prime is 6407535378763. The reversal of 6407535378721 is 1278735357046.

The square root of 6407535378721 is 2531311.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 233622389025 + 6173912989696 = 483345^2 + 2484736^2 .

It is not a de Polignac number, because 6407535378721 - 2¹¹ = 6407535376673 is a prime.

It is a super-2 number, since 2×6407535378721² (a number of 26 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6407535378121) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 9140563671 + ... + 9140564371.

Almost surely, 2^{6407535378721} is an apocalyptic number.

6407535378721 is the 2531311-st square number.

6407535378721 is the 1265656-th centered octagonal number.

It is an amenable number.

6407535378721 is a deficient number, since it is larger than the sum of its proper divisors (343266935192).

6407535378721 is an frugal number, since it uses more digits than its factorization.

6407535378721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1762 (or 881 counting only the distinct ones).

The product of its (nonzero) digits is 29635200, while the sum is 58.

The spelling of 6407535378721 in words is "six trillion, four hundred seven billion, five hundred thirty-five million, three hundred seventy-eight thousand, seven hundred twenty-one".