1648021247 has 4 divisors (see below), whose sum is σ = 1648630080. Its totient is φ = 1647412416.

The previous prime is 1648021241. The next prime is 1648021253. The reversal of 1648021247 is 7421208461.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 7421208461 = 19 ⋅390589919.

It is an interprime number because it is at equal distance from previous prime (1648021241) and next prime (1648021253).

It is a cyclic number.

It is not a de Polignac number, because 1648021247 - 2²⁰ = 1646972671 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1648021241) 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, 300338 + ... + 305775.

It is an arithmetic number, because the mean of its divisors is an integer number (412157520).

Almost surely, 2^1648021247 is an apocalyptic number.

1648021247 is a deficient number, since it is larger than the sum of its proper divisors (608833).

1648021247 is an equidigital number, since it uses as much as digits as its factorization.

1648021247 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 608832.

The product of its (nonzero) digits is 21504, while the sum is 35.

The square root of 1648021247 is about 40595.8279506651. The cubic root of 1648021247 is about 1181.1931928972.

The spelling of 1648021247 in words is "one billion, six hundred forty-eight million, twenty-one thousand, two hundred forty-seven".