21770042542 has 4 divisors (see below), whose sum is σ = 32655063816. Its totient is φ = 10885021270.

The previous prime is 21770042513. The next prime is 21770042543. The reversal of 21770042542 is 24524007712.

It is a semiprime because it is the product of two primes.

It is a junction number, because it is equal to n+sod(n) for n = 21770042498 and 21770042507.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21770042543) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5442510634 + ... + 5442510637.

It is an arithmetic number, because the mean of its divisors is an integer number (8163765954).

Almost surely, 2^21770042542 is an apocalyptic number.

21770042542 is a deficient number, since it is larger than the sum of its proper divisors (10885021274).

21770042542 is a wasteful number, since it uses less digits than its factorization.

21770042542 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10885021273.

The product of its (nonzero) digits is 31360, while the sum is 34.

The spelling of 21770042542 in words is "twenty-one billion, seven hundred seventy million, forty-two thousand, five hundred forty-two".