201990691 has 24 divisors (see below), whose sum is σ = 248433360. Its totient is φ = 163749600.

The previous prime is 201990683. The next prime is 201990697. The reversal of 201990691 is 196099102.

It is not a de Polignac number, because 201990691 - 2³ = 201990683 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 201990691.

It is not an unprimeable number, because it can be changed into a prime (201990697) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 335791 + ... + 336391.

It is an arithmetic number, because the mean of its divisors is an integer number (10351390).

Almost surely, 2^201990691 is an apocalyptic number.

201990691 is the 8206-th hex number.

201990691 is a deficient number, since it is larger than the sum of its proper divisors (46442669).

201990691 is an frugal number, since it uses more digits than its factorization.

201990691 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 672 (or 627 counting only the distinct ones).

The product of its (nonzero) digits is 8748, while the sum is 37.

The square root of 201990691 is about 14212.3429103016. The cubic root of 201990691 is about 586.7374174673.

The spelling of 201990691 in words is "two hundred one million, nine hundred ninety thousand, six hundred ninety-one".