651108421 has 2 divisors, whose sum is σ = 651108422. Its totient is φ = 651108420.

The previous prime is 651108401. The next prime is 651108439. The reversal of 651108421 is 124801156.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 542657025 + 108451396 = 23295^2 + 10414^2 .

It is a cyclic number.

It is not a de Polignac number, because 651108421 - 2¹¹ = 651106373 is a prime.

It is a super-2 number, since 2×651108421² = 847884351794226482, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 651108421.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (651108401) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 325554210 + 325554211.

It is an arithmetic number, because the mean of its divisors is an integer number (325554211).

Almost surely, 2^651108421 is an apocalyptic number.

It is an amenable number.

651108421 is a deficient number, since it is larger than the sum of its proper divisors (1).

651108421 is an equidigital number, since it uses as much as digits as its factorization.

651108421 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1920, while the sum is 28.

The square root of 651108421 is about 25516.8262328997. The cubic root of 651108421 is about 866.7312142425.

Adding to 651108421 its reverse (124801156), we get a palindrome (775909577).

The spelling of 651108421 in words is "six hundred fifty-one million, one hundred eight thousand, four hundred twenty-one".