20543642631021 has 16 divisors (see below), whose sum is σ = 27647789833728. Its totient is φ = 13567631098800.

The previous prime is 20543642630999. The next prime is 20543642631067. The reversal of 20543642631021 is 12013624634502.

It is not a de Polignac number, because 20543642631021 - 2¹¹ = 20543642628973 is a prime.

It is a super-2 number, since 2×20543642631021² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20543642632021) 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, 40970736 + ... + 41469126.

It is an arithmetic number, because the mean of its divisors is an integer number (1727986864608).

Almost surely, 2^{20543642631021} is an apocalyptic number.

It is an amenable number.

20543642631021 is a deficient number, since it is larger than the sum of its proper divisors (7104147202707).

20543642631021 is a wasteful number, since it uses less digits than its factorization.

20543642631021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 626912.

The product of its (nonzero) digits is 207360, while the sum is 39.

The spelling of 20543642631021 in words is "twenty trillion, five hundred forty-three billion, six hundred forty-two million, six hundred thirty-one thousand, twenty-one".