21050142551 has 16 divisors (see below), whose sum is σ = 21892223808. Its totient is φ = 20224377600.

The previous prime is 21050142499. The next prime is 21050142571. The reversal of 21050142551 is 15524105012.

It is a cyclic number.

It is not a de Polignac number, because 21050142551 - 2³⁴ = 3870273367 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21050142551.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21050142571) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2898641 + ... + 2905893.

It is an arithmetic number, because the mean of its divisors is an integer number (1368263988).

Almost surely, 2^21050142551 is an apocalyptic number.

21050142551 is a deficient number, since it is larger than the sum of its proper divisors (842081257).

21050142551 is an equidigital number, since it uses as much as digits as its factorization.

21050142551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8362.

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

Adding to 21050142551 its reverse (15524105012), we get a palindrome (36574247563).

The spelling of 21050142551 in words is "twenty-one billion, fifty million, one hundred forty-two thousand, five hundred fifty-one".