1643683954 has 16 divisors (see below), whose sum is σ = 2723713920. Its totient is φ = 737670960.

The previous prime is 1643683919. The next prime is 1643683961. The reversal of 1643683954 is 4593863461.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 1643683898 and 1643683907.

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, 471129 + ... + 474604.

It is an arithmetic number, because the mean of its divisors is an integer number (170232120).

Almost surely, 2^1643683954 is an apocalyptic number.

1643683954 is a deficient number, since it is larger than the sum of its proper divisors (1080029966).

1643683954 is a wasteful number, since it uses less digits than its factorization.

1643683954 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 945825.

The product of its digits is 1866240, while the sum is 49.

The square root of 1643683954 is about 40542.3723282198. The cubic root of 1643683954 is about 1180.1560537651.

The spelling of 1643683954 in words is "one billion, six hundred forty-three million, six hundred eighty-three thousand, nine hundred fifty-four".