201521154097 has 4 divisors (see below), whose sum is σ = 204824779636. Its totient is φ = 198217528560.

The previous prime is 201521154071. The next prime is 201521154113. The reversal of 201521154097 is 790451125102.

201521154097 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 23005608976 + 178515545121 = 151676^2 + 422511^2 .

It is a cyclic number.

It is not a de Polignac number, because 201521154097 - 2¹⁹ = 201520629809 is a prime.

It is a super-2 number, since 2×201521154097² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (201521154067) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1651812678 + ... + 1651812799.

It is an arithmetic number, because the mean of its divisors is an integer number (51206194909).

Almost surely, 2^201521154097 is an apocalyptic number.

It is an amenable number.

201521154097 is a deficient number, since it is larger than the sum of its proper divisors (3303625539).

201521154097 is an equidigital number, since it uses as much as digits as its factorization.

201521154097 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3303625538.

The product of its (nonzero) digits is 25200, while the sum is 37.

Adding to 201521154097 its reverse (790451125102), we get a palindrome (991972279199).

The spelling of 201521154097 in words is "two hundred one billion, five hundred twenty-one million, one hundred fifty-four thousand, ninety-seven".