1684079881 has 4 divisors (see below), whose sum is σ = 1837178064. Its totient is φ = 1530981700.

The previous prime is 1684079869. The next prime is 1684079899. The reversal of 1684079881 is 1889704861.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1684079881 is a prime.

It is a super-2 number, since 2×1684079881² = 5672250091177948322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1684079861) 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, 76549075 + ... + 76549096.

It is an arithmetic number, because the mean of its divisors is an integer number (459294516).

Almost surely, 2^1684079881 is an apocalyptic number.

1684079881 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1684079881 is a deficient number, since it is larger than the sum of its proper divisors (153098183).

1684079881 is a wasteful number, since it uses less digits than its factorization.

1684079881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 153098182.

The product of its (nonzero) digits is 774144, while the sum is 52.

The square root of 1684079881 is about 41037.5423362560. The cubic root of 1684079881 is about 1189.7459338027.

It can be divided in two parts, 16840 and 79881, that added together give a square (96721 = 311²).

The spelling of 1684079881 in words is "one billion, six hundred eighty-four million, seventy-nine thousand, eight hundred eighty-one".