20400002421 has 32 divisors (see below), whose sum is σ = 28530835200. Its totient is φ = 12940967424.

The previous prime is 20400002419. The next prime is 20400002449. The reversal of 20400002421 is 12420000402.

It is not a de Polignac number, because 20400002421 - 2¹ = 20400002419 is a prime.

It is a super-2 number, since 2×20400002421² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 20400002421.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20400002461) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 14857291 + ... + 14858663.

It is an arithmetic number, because the mean of its divisors is an integer number (891588600).

Almost surely, 2^20400002421 is an apocalyptic number.

It is an amenable number.

20400002421 is a deficient number, since it is larger than the sum of its proper divisors (8130832779).

20400002421 is a wasteful number, since it uses less digits than its factorization.

20400002421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2365.

The product of its (nonzero) digits is 128, while the sum is 15.

Adding to 20400002421 its reverse (12420000402), we get a palindrome (32820002823).

The spelling of 20400002421 in words is "twenty billion, four hundred million, two thousand, four hundred twenty-one".