651212981 has 2 divisors, whose sum is σ = 651212982. Its totient is φ = 651212980.

The previous prime is 651212977. The next prime is 651213047. The reversal of 651212981 is 189212156.

651212981 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 598780900 + 52432081 = 24470^2 + 7241^2 .

It is a cyclic number.

It is not a de Polignac number, because 651212981 - 2² = 651212977 is a prime.

It is a super-2 number, since 2×651212981² = 848156693245812722, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (651217981) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 325606490 + 325606491.

It is an arithmetic number, because the mean of its divisors is an integer number (325606491).

Almost surely, 2^651212981 is an apocalyptic number.

It is an amenable number.

651212981 is a deficient number, since it is larger than the sum of its proper divisors (1).

651212981 is an equidigital number, since it uses as much as digits as its factorization.

651212981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 8640, while the sum is 35.

The square root of 651212981 is about 25518.8749947955. The cubic root of 651212981 is about 866.7776072149. Note that the first 3 decimals are identical.

The spelling of 651212981 in words is "six hundred fifty-one million, two hundred twelve thousand, nine hundred eighty-one".