646622722 has 4 divisors (see below), whose sum is σ = 969934086. Its totient is φ = 323311360.

The previous prime is 646622719. The next prime is 646622747. The reversal of 646622722 is 227226646.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 227226646 = 2 ⋅113613323.

It can be written as a sum of positive squares in only one way, i.e., 555592041 + 91030681 = 23571^2 + 9541^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 161655679 + ... + 161655682.

Almost surely, 2^646622722 is an apocalyptic number.

646622722 is a deficient number, since it is larger than the sum of its proper divisors (323311364).

646622722 is a wasteful number, since it uses less digits than its factorization.

646622722 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 323311363.

The product of its digits is 96768, while the sum is 37.

The square root of 646622722 is about 25428.7774381703. Note that the first 3 decimals coincide. The cubic root of 646622722 is about 864.7362275023.

The spelling of 646622722 in words is "six hundred forty-six million, six hundred twenty-two thousand, seven hundred twenty-two".