820861126551 has 12 divisors (see below), whose sum is σ = 1193540536240. Its totient is φ = 543616639200.

The previous prime is 820861126513. The next prime is 820861126601. The reversal of 820861126551 is 155621168028.

820861126551 is a `hidden beast` number, since 8 + 2 + 0 + 8 + 611 + 26 + 5 + 5 + 1 = 666.

It is not a de Polignac number, because 820861126551 - 2³⁰ = 819787384727 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 820861126497 and 820861126506.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (820861126451) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 302007886 + ... + 302010603.

Almost surely, 2^820861126551 is an apocalyptic number.

820861126551 is a deficient number, since it is larger than the sum of its proper divisors (372679409689).

820861126551 is a wasteful number, since it uses less digits than its factorization.

820861126551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 604018646 (or 604018643 counting only the distinct ones).

The product of its (nonzero) digits is 230400, while the sum is 45.

The spelling of 820861126551 in words is "eight hundred twenty billion, eight hundred sixty-one million, one hundred twenty-six thousand, five hundred fifty-one".