201521542 has 4 divisors (see below), whose sum is σ = 302282316. Its totient is φ = 100760770.

The previous prime is 201521539. The next prime is 201521557. The reversal of 201521542 is 245125102.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 245125102 = 2 ⋅122562551.

It is a super-2 number, since 2×201521542² = 81221863780115528, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 50380384 + ... + 50380387.

It is an arithmetic number, because the mean of its divisors is an integer number (75570579).

Almost surely, 2^201521542 is an apocalyptic number.

201521542 is a deficient number, since it is larger than the sum of its proper divisors (100760774).

201521542 is a wasteful number, since it uses less digits than its factorization.

201521542 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 100760773.

The product of its (nonzero) digits is 800, while the sum is 22.

The square root of 201521542 is about 14195.8283308865. The cubic root of 201521542 is about 586.2828079651.

Adding to 201521542 its reverse (245125102), we get a palindrome (446646644).

The spelling of 201521542 in words is "two hundred one million, five hundred twenty-one thousand, five hundred forty-two".