21203004042 has 40 divisors (see below), whose sum is σ = 51829569792. Its totient is φ = 6425152200.

The previous prime is 21203004037. The next prime is 21203004047. The reversal of 21203004042 is 24040030212.

It is an interprime number because it is at equal distance from previous prime (21203004037) and next prime (21203004047).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is not an unprimeable number, because it can be changed into a prime (21203004047) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 5947434 + ... + 5950997.

Almost surely, 2^21203004042 is an apocalyptic number.

21203004042 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

21203004042 is an abundant number, since it is smaller than the sum of its proper divisors (30626565750).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21203004042 is a wasteful number, since it uses less digits than its factorization.

21203004042 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11898456 (or 11898447 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 18.

Adding to 21203004042 its reverse (24040030212), we get a palindrome (45243034254).

The spelling of 21203004042 in words is "twenty-one billion, two hundred three million, four thousand, forty-two".