210139661 has 8 divisors (see below), whose sum is σ = 221005824. Its totient is φ = 199417680.

The previous prime is 210139609. The next prime is 210139681. The reversal of 210139661 is 166931012.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 210139661 - 2¹⁰ = 210138637 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (210139681) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 33050 + ... + 38891.

It is an arithmetic number, because the mean of its divisors is an integer number (27625728).

Almost surely, 2^210139661 is an apocalyptic number.

It is an amenable number.

210139661 is a deficient number, since it is larger than the sum of its proper divisors (10866163).

210139661 is a wasteful number, since it uses less digits than its factorization.

210139661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 72091.

The product of its (nonzero) digits is 1944, while the sum is 29.

The square root of 210139661 is about 14496.1947075776. The cubic root of 210139661 is about 594.5239333913.

The spelling of 210139661 in words is "two hundred ten million, one hundred thirty-nine thousand, six hundred sixty-one".