647621046251 has 4 divisors (see below), whose sum is σ = 651909927504. Its totient is φ = 643332165000.

The previous prime is 647621046229. The next prime is 647621046263. The reversal of 647621046251 is 152640126746.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 152640126746 = 2 ⋅76320063373.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-647621046251 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (647621046151) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2144440400 + ... + 2144440701.

It is an arithmetic number, because the mean of its divisors is an integer number (162977481876).

Almost surely, 2^647621046251 is an apocalyptic number.

647621046251 is a deficient number, since it is larger than the sum of its proper divisors (4288881253).

647621046251 is a wasteful number, since it uses less digits than its factorization.

647621046251 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4288881252.

The product of its (nonzero) digits is 483840, while the sum is 44.

The spelling of 647621046251 in words is "six hundred forty-seven billion, six hundred twenty-one million, forty-six thousand, two hundred fifty-one".