651645351261 has 6 divisors (see below), whose sum is σ = 941265507390. Its totient is φ = 434430234168.

The previous prime is 651645351241. The next prime is 651645351311. The reversal of 651645351261 is 162153546156.

651645351261 is a `hidden beast` number, since 6 + 51 + 6 + 4 + 535 + 1 + 2 + 61 = 666.

It can be written as a sum of positive squares in only one way, i.e., 568048616100 + 83596735161 = 753690^2 + 289131^2 .

It is not a de Polignac number, because 651645351261 - 2⁹ = 651645350749 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (651645351221) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 36202519506 + ... + 36202519523.

It is an arithmetic number, because the mean of its divisors is an integer number (156877584565).

Almost surely, 2^651645351261 is an apocalyptic number.

It is an amenable number.

651645351261 is a deficient number, since it is larger than the sum of its proper divisors (289620156129).

651645351261 is a wasteful number, since it uses less digits than its factorization.

651645351261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 72405039035 (or 72405039032 counting only the distinct ones).

The product of its digits is 648000, while the sum is 45.

The spelling of 651645351261 in words is "six hundred fifty-one billion, six hundred forty-five million, three hundred fifty-one thousand, two hundred sixty-one".