21040031428 has 48 divisors (see below), whose sum is σ = 40353510960. Its totient is φ = 9539481600.

The previous prime is 21040031393. The next prime is 21040031429. The reversal of 21040031428 is 82413004012.

It can be written as a sum of positive squares in 8 ways, for example, as 9993601024 + 11046430404 = 99968^2 + 105102^2 .

It is not an unprimeable number, because it can be changed into a prime (21040031429) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2790768 + ... + 2798296.

It is an arithmetic number, because the mean of its divisors is an integer number (840698145).

Almost surely, 2^21040031428 is an apocalyptic number.

It is an amenable number.

21040031428 is a deficient number, since it is larger than the sum of its proper divisors (19313479532).

21040031428 is a wasteful number, since it uses less digits than its factorization.

21040031428 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8488 (or 8486 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 25.

The spelling of 21040031428 in words is "twenty-one billion, forty million, thirty-one thousand, four hundred twenty-eight".