1661629838 has 48 divisors (see below), whose sum is σ = 2894346000. Its totient is φ = 712926720.

The previous prime is 1661629829. The next prime is 1661629841. The reversal of 1661629838 is 8389261661.

It is a super-3 number, since 3×1661629838³ (a number of 29 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1788158 + ... + 1789086.

It is an arithmetic number, because the mean of its divisors is an integer number (60298875).

Almost surely, 2^1661629838 is an apocalyptic number.

1661629838 is a deficient number, since it is larger than the sum of its proper divisors (1232716162).

1661629838 is a wasteful number, since it uses less digits than its factorization.

1661629838 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1361 (or 1350 counting only the distinct ones).

The product of its digits is 746496, while the sum is 50.

The square root of 1661629838 is about 40763.0940680415. The cubic root of 1661629838 is about 1184.4355321670.

The spelling of 1661629838 in words is "one billion, six hundred sixty-one million, six hundred twenty-nine thousand, eight hundred thirty-eight".