21003431004 has 48 divisors (see below), whose sum is σ = 55376294400. Its totient is φ = 6882478128.

The previous prime is 21003430999. The next prime is 21003431011. The reversal of 21003431004 is 40013430012.

It is a super-2 number, since 2×21003431004² (a number of 21 digits) contains 22 as substring.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1641732 + ... + 1654475.

It is an arithmetic number, because the mean of its divisors is an integer number (1153672800).

Almost surely, 2^21003431004 is an apocalyptic number.

It is an amenable number.

21003431004 is an abundant number, since it is smaller than the sum of its proper divisors (34372863396).

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

21003431004 is a wasteful number, since it uses less digits than its factorization.

21003431004 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3296279 (or 3296271 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 18.

Adding to 21003431004 its reverse (40013430012), we get a palindrome (61016861016).

The spelling of 21003431004 in words is "twenty-one billion, three million, four hundred thirty-one thousand, four".