20521010651 has 4 divisors (see below), whose sum is σ = 20536476192. Its totient is φ = 20505545112.

The previous prime is 20521010603. The next prime is 20521010659. The reversal of 20521010651 is 15601012502.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 20521010651 - 2¹⁰ = 20521009627 is a prime.

It is a super-2 number, since 2×20521010651² (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 (20521010659) 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, 7730780 + ... + 7733433.

It is an arithmetic number, because the mean of its divisors is an integer number (5134119048).

Almost surely, 2^20521010651 is an apocalyptic number.

20521010651 is a deficient number, since it is larger than the sum of its proper divisors (15465541).

20521010651 is a wasteful number, since it uses less digits than its factorization.

20521010651 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15465540.

The product of its (nonzero) digits is 600, while the sum is 23.

The spelling of 20521010651 in words is "twenty billion, five hundred twenty-one million, ten thousand, six hundred fifty-one".