648162391 has 4 divisors (see below), whose sum is σ = 648243000. Its totient is φ = 648081784.

The previous prime is 648162343. The next prime is 648162419. The reversal of 648162391 is 193261846.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 193261846 = 2 ⋅96630923.

It is a cyclic number.

It is not a de Polignac number, because 648162391 - 2¹⁵ = 648129623 is a prime.

It is a super-2 number, since 2×648162391² = 840228970213673762, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (648162301) 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, 26716 + ... + 44833.

It is an arithmetic number, because the mean of its divisors is an integer number (162060750).

Almost surely, 2^648162391 is an apocalyptic number.

648162391 is a deficient number, since it is larger than the sum of its proper divisors (80609).

648162391 is an equidigital number, since it uses as much as digits as its factorization.

648162391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 80608.

The product of its digits is 62208, while the sum is 40.

The square root of 648162391 is about 25459.0335833865. The cubic root of 648162391 is about 865.4220226746.

The spelling of 648162391 in words is "six hundred forty-eight million, one hundred sixty-two thousand, three hundred ninety-one".