20551352110991 has 4 divisors (see below), whose sum is σ = 22132225350312. Its totient is φ = 18970478871672.

The previous prime is 20551352110963. The next prime is 20551352110999. The reversal of 20551352110991 is 19901125315502.

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 20551352110991 - 2¹⁸ = 20551351848847 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20551352110999) 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, 790436619641 + ... + 790436619666.

It is an arithmetic number, because the mean of its divisors is an integer number (5533056337578).

Almost surely, 2^{20551352110991} is an apocalyptic number.

20551352110991 is a deficient number, since it is larger than the sum of its proper divisors (1580873239321).

20551352110991 is a wasteful number, since it uses less digits than its factorization.

20551352110991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1580873239320.

The product of its (nonzero) digits is 121500, while the sum is 44.

The spelling of 20551352110991 in words is "twenty trillion, five hundred fifty-one billion, three hundred fifty-two million, one hundred ten thousand, nine hundred ninety-one".