1390486697721 has 135 divisors (see below), whose sum is σ = 2345945021343. Its totient is φ = 820149533280.

The previous prime is 1390486697707. The next prime is 1390486697729. The reversal of 1390486697721 is 1277966840931.

The square root of 1390486697721 is 1179189.

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

1390486697721 is a `hidden beast` number, since 1 + 3 + 9 + 0 + 486 + 69 + 77 + 21 = 666.

It can be written as a sum of positive squares in only one way, i.e., 239664098025 + 1150822599696 = 489555^2 + 1072764^2 .

It is not a de Polignac number, because 1390486697721 - 2⁵ = 1390486697689 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1390486697729) by changing a digit.

It is a polite number, since it can be written in 134 ways as a sum of consecutive naturals, for example, 5019807435 + ... + 5019807711.

Almost surely, 2^{1390486697721} is an apocalyptic number.

1390486697721 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

1390486697721 is the 1179189-th square number.

1390486697721 is the 589595-th centered octagonal number.

It is an amenable number.

1390486697721 is a deficient number, since it is larger than the sum of its proper divisors (955458323622).

1390486697721 is an frugal number, since it uses more digits than its factorization.

1390486697721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 674 (or 334 counting only the distinct ones).

The product of its (nonzero) digits is 27433728, while the sum is 63.

The spelling of 1390486697721 in words is "one trillion, three hundred ninety billion, four hundred eighty-six million, six hundred ninety-seven thousand, seven hundred twenty-one".