651106221521 has 4 divisors (see below), whose sum is σ = 744121396032. Its totient is φ = 558091047012.

The previous prime is 651106221503. The next prime is 651106221529. The reversal of 651106221521 is 125122601156.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 651106221521 - 2¹⁸ = 651105959377 is a prime.

It is not an unprimeable number, because it can be changed into a prime (651106221529) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 46507587245 + ... + 46507587258.

It is an arithmetic number, because the mean of its divisors is an integer number (186030349008).

Almost surely, 2^651106221521 is an apocalyptic number.

It is an amenable number.

651106221521 is a deficient number, since it is larger than the sum of its proper divisors (93015174511).

651106221521 is an equidigital number, since it uses as much as digits as its factorization.

651106221521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 93015174510.

The product of its (nonzero) digits is 7200, while the sum is 32.

Adding to 651106221521 its reverse (125122601156), we get a palindrome (776228822677).

The spelling of 651106221521 in words is "six hundred fifty-one billion, one hundred six million, two hundred twenty-one thousand, five hundred twenty-one".