7087921021 has 4 divisors (see below), whose sum is σ = 7279486492. Its totient is φ = 6896355552.

The previous prime is 7087921019. The next prime is 7087921031. The reversal of 7087921021 is 1201297807.

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 3876432121 + 3211488900 = 62261^2 + 56670^2 .

It is a cyclic number.

It is not a de Polignac number, because 7087921021 - 2¹ = 7087921019 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (37), and also a Moran number because the ratio is a prime number: 191565433 = 7087921021 / (7 + 0 + 8 + 7 + 9 + 2 + 1 + 0 + 2 + 1).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7087921031) 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, 95782680 + ... + 95782753.

It is an arithmetic number, because the mean of its divisors is an integer number (1819871623).

Almost surely, 2^7087921021 is an apocalyptic number.

It is an amenable number.

7087921021 is a deficient number, since it is larger than the sum of its proper divisors (191565471).

7087921021 is a wasteful number, since it uses less digits than its factorization.

7087921021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 191565470.

The product of its (nonzero) digits is 14112, while the sum is 37.

The square root of 7087921021 is about 84189.7916673987. The cubic root of 7087921021 is about 1920.9067820523.

The spelling of 7087921021 in words is "seven billion, eighty-seven million, nine hundred twenty-one thousand, twenty-one".