201821525 has 12 divisors (see below), whose sum is σ = 255584832. Its totient is φ = 158021040.

The previous prime is 201821519. The next prime is 201821531. The reversal of 201821525 is 525128102.

It is an interprime number because it is at equal distance from previous prime (201821519) and next prime (201821531).

It is not a de Polignac number, because 201821525 - 2¹⁰ = 201820501 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 201821494 and 201821503.

It is a congruent number.

It is an unprimeable number.

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 11 ways as a sum of consecutive naturals, for example, 84707 + ... + 87056.

It is an arithmetic number, because the mean of its divisors is an integer number (21298736).

Almost surely, 2^201821525 is an apocalyptic number.

201821525 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

201821525 is a deficient number, since it is larger than the sum of its proper divisors (53763307).

201821525 is a wasteful number, since it uses less digits than its factorization.

201821525 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 171820 (or 171815 counting only the distinct ones).

The product of its (nonzero) digits is 1600, while the sum is 26.

The square root of 201821525 is about 14206.3902874727. The cubic root of 201821525 is about 586.5735753563.

Adding to 201821525 its reverse (525128102), we get a palindrome (726949627).

The spelling of 201821525 in words is "two hundred one million, eight hundred twenty-one thousand, five hundred twenty-five".