1649913881 has 32 divisors (see below), whose sum is σ = 2086753536. Its totient is φ = 1267200000.

The previous prime is 1649913871. The next prime is 1649913943. The reversal of 1649913881 is 1883199461.

It is not a de Polignac number, because 1649913881 - 2⁶ = 1649913817 is a prime.

It is a super-2 number, since 2×1649913881² = 5444431629432964322, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1649913851) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2744981 + ... + 2745581.

It is an arithmetic number, because the mean of its divisors is an integer number (65211048).

Almost surely, 2^1649913881 is an apocalyptic number.

1649913881 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1649913881 is a deficient number, since it is larger than the sum of its proper divisors (436839655).

1649913881 is a wasteful number, since it uses less digits than its factorization.

1649913881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1073.

The product of its digits is 373248, while the sum is 50.

The square root of 1649913881 is about 40619.1319577364. The cubic root of 1649913881 is about 1181.6451917517.

The spelling of 1649913881 in words is "one billion, six hundred forty-nine million, nine hundred thirteen thousand, eight hundred eighty-one".