21040261404 has 24 divisors (see below), whose sum is σ = 49314101760. Its totient is φ = 6981969264.

The previous prime is 21040261351. The next prime is 21040261433. The reversal of 21040261404 is 40416204012.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3928614 + ... + 3933965.

It is an arithmetic number, because the mean of its divisors is an integer number (2054754240).

Almost surely, 2^21040261404 is an apocalyptic number.

It is an amenable number.

21040261404 is an abundant number, since it is smaller than the sum of its proper divisors (28273840356).

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

21040261404 is a wasteful number, since it uses less digits than its factorization.

21040261404 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7862809 (or 7862807 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 24.

Adding to 21040261404 its reverse (40416204012), we get a palindrome (61456465416).

The spelling of 21040261404 in words is "twenty-one billion, forty million, two hundred sixty-one thousand, four hundred four".