20521121601 has 8 divisors (see below), whose sum is σ = 28028849184. Its totient is φ = 13347070880.

The previous prime is 20521121597. The next prime is 20521121611. The reversal of 20521121601 is 10612112502.

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 20521121601 - 2² = 20521121597 is a prime.

It is a super-2 number, since 2×20521121601² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (20521121611) 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, 83419071 + ... + 83419316.

It is an arithmetic number, because the mean of its divisors is an integer number (3503606148).

Almost surely, 2^20521121601 is an apocalyptic number.

It is an amenable number.

20521121601 is a deficient number, since it is larger than the sum of its proper divisors (7507727583).

20521121601 is a wasteful number, since it uses less digits than its factorization.

20521121601 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 166838431.

The product of its (nonzero) digits is 240, while the sum is 21.

Subtracting from 20521121601 its reverse (10612112502), we obtain a palindrome (9909009099).

The spelling of 20521121601 in words is "twenty billion, five hundred twenty-one million, one hundred twenty-one thousand, six hundred one".