201851551 has 8 divisors (see below), whose sum is σ = 220630608. Its totient is φ = 183144000.

The previous prime is 201851549. The next prime is 201851563. The reversal of 201851551 is 155158102.

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 201851551 - 2¹ = 201851549 is a prime.

It is a super-2 number, since 2×201851551² = 81488097282211202, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (201851521) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11880 + ... + 23341.

It is an arithmetic number, because the mean of its divisors is an integer number (27578826).

Almost surely, 2^201851551 is an apocalyptic number.

201851551 is a deficient number, since it is larger than the sum of its proper divisors (18779057).

201851551 is a wasteful number, since it uses less digits than its factorization.

201851551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35753.

The product of its (nonzero) digits is 2000, while the sum is 28.

The square root of 201851551 is about 14207.4470261198. The cubic root of 201851551 is about 586.6026630776.

It can be divided in two parts, 20185 and 1551, that added together give a triangular number (21736 = T₂₀₈).

The spelling of 201851551 in words is "two hundred one million, eight hundred fifty-one thousand, five hundred fifty-one".