1648361781 has 24 divisors (see below), whose sum is σ = 2630309760. Its totient is φ = 986356800.

The previous prime is 1648361761. The next prime is 1648361789. The reversal of 1648361781 is 1871638461.

It is not a de Polignac number, because 1648361781 - 2⁵ = 1648361749 is a prime.

It is a super-2 number, since 2×1648361781² = 5434193122122983922, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1648361789) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 97560 + ... + 113201.

It is an arithmetic number, because the mean of its divisors is an integer number (109596240).

Almost surely, 2^1648361781 is an apocalyptic number.

1648361781 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1648361781 is a deficient number, since it is larger than the sum of its proper divisors (981947979).

1648361781 is a wasteful number, since it uses less digits than its factorization.

1648361781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 210857 (or 210854 counting only the distinct ones).

The product of its digits is 193536, while the sum is 45.

The square root of 1648361781 is about 40600.0219334916. The cubic root of 1648361781 is about 1181.2745447491.

The spelling of 1648361781 in words is "one billion, six hundred forty-eight million, three hundred sixty-one thousand, seven hundred eighty-one".