20782641551 has 4 divisors (see below), whose sum is σ = 23751590352. Its totient is φ = 17813692752.

The previous prime is 20782641527. The next prime is 20782641571. The reversal of 20782641551 is 15514628702.

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 20782641551 - 2²² = 20778447247 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20782641499 and 20782641508.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20782641511) 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, 1484474390 + ... + 1484474403.

It is an arithmetic number, because the mean of its divisors is an integer number (5937897588).

Almost surely, 2^20782641551 is an apocalyptic number.

20782641551 is a deficient number, since it is larger than the sum of its proper divisors (2968948801).

20782641551 is an equidigital number, since it uses as much as digits as its factorization.

20782641551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2968948800.

The product of its (nonzero) digits is 134400, while the sum is 41.

The spelling of 20782641551 in words is "twenty billion, seven hundred eighty-two million, six hundred forty-one thousand, five hundred fifty-one".