51509651 has 2 divisors, whose sum is σ = 51509652. Its totient is φ = 51509650.

The previous prime is 51509641. The next prime is 51509683. The reversal of 51509651 is 15690515.

It is an a-pointer prime, because the next prime (51509683) can be obtained adding 51509651 to its sum of digits (32).

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 51509651 - 2¹⁰ = 51508627 is a prime.

It is a super-2 number, since 2×51509651² = 5306488292283602, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (51509621) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25754825 + 25754826.

It is an arithmetic number, because the mean of its divisors is an integer number (25754826).

Almost surely, 2^51509651 is an apocalyptic number.

51509651 is a deficient number, since it is larger than the sum of its proper divisors (1).

51509651 is an equidigital number, since it uses as much as digits as its factorization.

51509651 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6750, while the sum is 32.

The square root of 51509651 is about 7177.0224327363. The cubic root of 51509651 is about 372.0741821267.

The spelling of 51509651 in words is "fifty-one million, five hundred nine thousand, six hundred fifty-one".