7722977921 has 8 divisors (see below), whose sum is σ = 7938105000. Its totient is φ = 7508187648.

The previous prime is 7722977917. The next prime is 7722977939. The reversal of 7722977921 is 1297792277.

It can be written as a sum of positive squares in 4 ways, for example, as 3185473600 + 4537504321 = 56440^2 + 67361^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 7722977921 - 2² = 7722977917 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (7722997921) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 37346 + ... + 129771.

It is an arithmetic number, because the mean of its divisors is an integer number (992263125).

Almost surely, 2^7722977921 is an apocalyptic number.

It is an amenable number.

7722977921 is a deficient number, since it is larger than the sum of its proper divisors (215127079).

7722977921 is a wasteful number, since it uses less digits than its factorization.

7722977921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 168403.

The product of its digits is 1555848, while the sum is 53.

The square root of 7722977921 is about 87880.4751978504. The cubic root of 7722977921 is about 1976.6431165995.

The spelling of 7722977921 in words is "seven billion, seven hundred twenty-two million, nine hundred seventy-seven thousand, nine hundred twenty-one".