20513437253021 has 4 divisors (see below), whose sum is σ = 20802358904544. Its totient is φ = 20224515601500.

The previous prime is 20513437252963. The next prime is 20513437253041. The reversal of 20513437253021 is 12035273431502.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 20513437253021 - 2¹⁸ = 20513436990877 is a prime.

It is a super-2 number, since 2×20513437253021² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20513437253041) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 144460825655 + ... + 144460825796.

It is an arithmetic number, because the mean of its divisors is an integer number (5200589726136).

Almost surely, 2^{20513437253021} is an apocalyptic number.

It is an amenable number.

20513437253021 is a deficient number, since it is larger than the sum of its proper divisors (288921651523).

20513437253021 is an equidigital number, since it uses as much as digits as its factorization.

20513437253021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 288921651522.

The product of its (nonzero) digits is 151200, while the sum is 38.

The spelling of 20513437253021 in words is "twenty trillion, five hundred thirteen billion, four hundred thirty-seven million, two hundred fifty-three thousand, twenty-one".