20157020521 has 8 divisors (see below), whose sum is σ = 22016205504. Its totient is φ = 18302290320.

The previous prime is 20157020509. The next prime is 20157020591. The reversal of 20157020521 is 12502075102.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20157020521 is a prime.

It is a super-2 number, since 2×20157020521² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20157020501) 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 7 ways as a sum of consecutive naturals, for example, 1104226 + ... + 1122331.

It is an arithmetic number, because the mean of its divisors is an integer number (2752025688).

Almost surely, 2^20157020521 is an apocalyptic number.

It is an amenable number.

20157020521 is a deficient number, since it is larger than the sum of its proper divisors (1859184983).

20157020521 is a wasteful number, since it uses less digits than its factorization.

20157020521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2227391.

The product of its (nonzero) digits is 1400, while the sum is 25.

Adding to 20157020521 its reverse (12502075102), we get a palindrome (32659095623).

The spelling of 20157020521 in words is "twenty billion, one hundred fifty-seven million, twenty thousand, five hundred twenty-one".