61421824857 has 16 divisors (see below), whose sum is σ = 86766774912. Its totient is φ = 38515357440.

The previous prime is 61421824847. The next prime is 61421824873. The reversal of 61421824857 is 75842812416.

It is a happy number.

61421824857 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 61421824857 - 2⁸ = 61421824601 is a prime.

It is not an unprimeable number, because it can be changed into a prime (61421824847) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 288813 + ... + 454154.

It is an arithmetic number, because the mean of its divisors is an integer number (5422923432).

Almost surely, 2^61421824857 is an apocalyptic number.

It is an amenable number.

61421824857 is a deficient number, since it is larger than the sum of its proper divisors (25344950055).

61421824857 is a wasteful number, since it uses less digits than its factorization.

61421824857 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 744608.

The product of its digits is 860160, while the sum is 48.

The spelling of 61421824857 in words is "sixty-one billion, four hundred twenty-one million, eight hundred twenty-four thousand, eight hundred fifty-seven".