21202405040 has 20 divisors (see below), whose sum is σ = 49295591904. Its totient is φ = 8480961984.

The previous prime is 21202405013. The next prime is 21202405061. The reversal of 21202405040 is 4050420212.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (20).

It is a Harshad number since it is a multiple of its sum of digits (20).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 132514952 + ... + 132515111.

Almost surely, 2^21202405040 is an apocalyptic number.

21202405040 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21202405040 is an abundant number, since it is smaller than the sum of its proper divisors (28093186864).

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

21202405040 is a wasteful number, since it uses less digits than its factorization.

21202405040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 265030076 (or 265030070 counting only the distinct ones).

The product of its (nonzero) digits is 640, while the sum is 20.

Adding to 21202405040 its reverse (4050420212), we get a palindrome (25252825252).

The spelling of 21202405040 in words is "twenty-one billion, two hundred two million, four hundred five thousand, forty".