20551401521 has 8 divisors (see below), whose sum is σ = 23618531520. Its totient is φ = 17517075408.

The previous prime is 20551401469. The next prime is 20551401569. The reversal of 20551401521 is 12510415502.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 20551401521 - 2⁶ = 20551401457 is a prime.

It is a super-2 number, since 2×20551401521² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (20551401571) 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, 8199626 + ... + 8202131.

It is an arithmetic number, because the mean of its divisors is an integer number (2952316440).

Almost surely, 2^20551401521 is an apocalyptic number.

It is an amenable number.

20551401521 is a deficient number, since it is larger than the sum of its proper divisors (3067129999).

20551401521 is a wasteful number, since it uses less digits than its factorization.

20551401521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16401943.

The product of its (nonzero) digits is 2000, while the sum is 26.

The spelling of 20551401521 in words is "twenty billion, five hundred fifty-one million, four hundred one thousand, five hundred twenty-one".