20521431436 has 48 divisors (see below), whose sum is σ = 39411066240. Its totient is φ = 9272430720.

The previous prime is 20521431433. The next prime is 20521431451. The reversal of 20521431436 is 63413412502.

It is a super-2 number, since 2×20521431436² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 20521431398 and 20521431407.

It is not an unprimeable number, because it can be changed into a prime (20521431431) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5813320 + ... + 5816848.

It is an arithmetic number, because the mean of its divisors is an integer number (821063880).

Almost surely, 2^20521431436 is an apocalyptic number.

It is an amenable number.

20521431436 is a deficient number, since it is larger than the sum of its proper divisors (18889634804).

20521431436 is a wasteful number, since it uses less digits than its factorization.

20521431436 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4294 (or 4292 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 31.

Adding to 20521431436 its reverse (63413412502), we get a palindrome (83934843938).

The spelling of 20521431436 in words is "twenty billion, five hundred twenty-one million, four hundred thirty-one thousand, four hundred thirty-six".