21858439157 has 4 divisors (see below), whose sum is σ = 21862691136. Its totient is φ = 21854187180.

The previous prime is 21858439133. The next prime is 21858439201. The reversal of 21858439157 is 75193485812.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21858439157 - 2⁶ = 21858439093 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21858439099 and 21858439108.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21858439657) 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, 2118269 + ... + 2128562.

It is an arithmetic number, because the mean of its divisors is an integer number (5465672784).

Almost surely, 2^21858439157 is an apocalyptic number.

It is an amenable number.

21858439157 is a deficient number, since it is larger than the sum of its proper divisors (4251979).

21858439157 is an equidigital number, since it uses as much as digits as its factorization.

21858439157 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4251978.

The product of its digits is 2419200, while the sum is 53.

The spelling of 21858439157 in words is "twenty-one billion, eight hundred fifty-eight million, four hundred thirty-nine thousand, one hundred fifty-seven".