100561404551 has 4 divisors (see below), whose sum is σ = 101938958112. Its totient is φ = 99183850992.

The previous prime is 100561404539. The next prime is 100561404553. The reversal of 100561404551 is 155404165001.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 155404165001 = 19 ⋅8179166579.

It is a cyclic number.

It is not a de Polignac number, because 100561404551 - 2³⁰ = 99487662727 is a prime.

It is a super-2 number, since 2×100561404551² (a number of 23 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 (100561404553) 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, 688776671 + ... + 688776816.

It is an arithmetic number, because the mean of its divisors is an integer number (25484739528).

Almost surely, 2^100561404551 is an apocalyptic number.

100561404551 is a deficient number, since it is larger than the sum of its proper divisors (1377553561).

100561404551 is an equidigital number, since it uses as much as digits as its factorization.

100561404551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1377553560.

The product of its (nonzero) digits is 12000, while the sum is 32.

Adding to 100561404551 its reverse (155404165001), we get a palindrome (255965569552).

The spelling of 100561404551 in words is "one hundred billion, five hundred sixty-one million, four hundred four thousand, five hundred fifty-one".