651563881 has 4 divisors (see below), whose sum is σ = 651717252. Its totient is φ = 651410512.

The previous prime is 651563873. The next prime is 651563893. The reversal of 651563881 is 188365156.

651563881 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 571640281 + 79923600 = 23909^2 + 8940^2 .

It is a cyclic number.

It is not a de Polignac number, because 651563881 - 2³ = 651563873 is a prime.

It is a super-2 number, since 2×651563881² = 849070982047564322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (651563281) 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, 70126 + ... + 78871.

It is an arithmetic number, because the mean of its divisors is an integer number (162929313).

Almost surely, 2^651563881 is an apocalyptic number.

It is an amenable number.

651563881 is a deficient number, since it is larger than the sum of its proper divisors (153371).

651563881 is a wasteful number, since it uses less digits than its factorization.

651563881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 153370.

The product of its digits is 172800, while the sum is 43.

The square root of 651563881 is about 25525.7493719577. The cubic root of 651563881 is about 866.9332642517.

The spelling of 651563881 in words is "six hundred fifty-one million, five hundred sixty-three thousand, eight hundred eighty-one".