21402469440 has 1008 divisors, whose sum is σ = 89710320960. Its totient is φ = 4628275200.

The previous prime is 21402469393. The next prime is 21402469463. The reversal of 21402469440 is 4496420412.

It is a happy number.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 21402469395 and 21402469404.

It is an unprimeable number.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 578445102 + ... + 578445138.

Almost surely, 2^21402469440 is an apocalyptic number.

21402469440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21402469440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (44855160480).

21402469440 is an abundant number, since it is smaller than the sum of its proper divisors (68307851520).

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

21402469440 is a wasteful number, since it uses less digits than its factorization.

21402469440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 152 (or 108 counting only the distinct ones).

The product of its (nonzero) digits is 55296, while the sum is 36.

Adding to 21402469440 its reverse (4496420412), we get a palindrome (25898889852).

The spelling of 21402469440 in words is "twenty-one billion, four hundred two million, four hundred sixty-nine thousand, four hundred forty".