7137387784921 has 3 divisors (see below), whose sum is σ = 7137390456511. Its totient is φ = 7137385113332.

The previous prime is 7137387784903. The next prime is 7137387784927. The reversal of 7137387784921 is 1294877837317.

The square root of 7137387784921 is 2671589.

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

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in only one way, i.e., 7085120680521 + 52267104400 = 2661789^2 + 228620^2 .

It is not a de Polignac number, because 7137387784921 - 2⁹ = 7137387784409 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (7137387784927) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 1335795 + ... + 4007383.

Almost surely, 2^{7137387784921} is an apocalyptic number.

7137387784921 is the 2671589-th square number.

7137387784921 is the 1335795-th centered octagonal number.

It is an amenable number.

7137387784921 is a deficient number, since it is larger than the sum of its proper divisors (2671590).

7137387784921 is an frugal number, since it uses more digits than its factorization.

7137387784921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5343178 (or 2671589 counting only the distinct ones).

The product of its digits is 99574272, while the sum is 67.

The spelling of 7137387784921 in words is "seven trillion, one hundred thirty-seven billion, three hundred eighty-seven million, seven hundred eighty-four thousand, nine hundred twenty-one".