21252256042 has 8 divisors (see below), whose sum is σ = 31993469316. Its totient is φ = 10587766272.

The previous prime is 21252256037. The next prime is 21252256043. The reversal of 21252256042 is 24065225212.

It can be written as a sum of positive squares in 2 ways, for example, as 19532578081 + 1719677961 = 139759^2 + 41469^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a junction number, because it is equal to n+sod(n) for n = 21252255995 and 21252256013.

It is not an unprimeable number, because it can be changed into a prime (21252256043) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 19180183 + ... + 19181290.

Almost surely, 2^21252256042 is an apocalyptic number.

21252256042 is a deficient number, since it is larger than the sum of its proper divisors (10741213274).

21252256042 is a wasteful number, since it uses less digits than its factorization.

21252256042 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38361752.

The product of its (nonzero) digits is 19200, while the sum is 31.

The spelling of 21252256042 in words is "twenty-one billion, two hundred fifty-two million, two hundred fifty-six thousand, forty-two".