1649261920 has 48 divisors (see below), whose sum is σ = 4065798240. Its totient is φ = 631020544.

The previous prime is 1649261909. The next prime is 1649261951. The reversal of 1649261920 is 291629461.

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 220405 + ... + 227764.

It is an arithmetic number, because the mean of its divisors is an integer number (84704130).

Almost surely, 2^1649261920 is an apocalyptic number.

1649261920 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1649261920 is an abundant number, since it is smaller than the sum of its proper divisors (2416536320).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1649261920 is a wasteful number, since it uses less digits than its factorization.

1649261920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 448207 (or 448199 counting only the distinct ones).

The product of its (nonzero) digits is 46656, while the sum is 40.

The square root of 1649261920 is about 40611.1058701927. The cubic root of 1649261920 is about 1181.4895294705.

The spelling of 1649261920 in words is "one billion, six hundred forty-nine million, two hundred sixty-one thousand, nine hundred twenty".