648437761 has 4 divisors (see below), whose sum is σ = 648495792. Its totient is φ = 648379732.

The previous prime is 648437759. The next prime is 648437813. The reversal of 648437761 is 167734846.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 167734846 = 2 ⋅83867423.

It is a cyclic number.

It is not a de Polignac number, because 648437761 - 2¹ = 648437759 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (648437861) 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, 6355 + ... + 36568.

It is an arithmetic number, because the mean of its divisors is an integer number (162123948).

Almost surely, 2^648437761 is an apocalyptic number.

It is an amenable number.

648437761 is a deficient number, since it is larger than the sum of its proper divisors (58031).

648437761 is a wasteful number, since it uses less digits than its factorization.

648437761 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 58030.

The product of its digits is 677376, while the sum is 46.

The square root of 648437761 is about 25464.4411091231. The cubic root of 648437761 is about 865.5445627073.

The spelling of 648437761 in words is "six hundred forty-eight million, four hundred thirty-seven thousand, seven hundred sixty-one".