21426172460 has 96 divisors (see below), whose sum is σ = 56133762048. Its totient is φ = 6673985280.

The previous prime is 21426172433. The next prime is 21426172463. The reversal of 21426172460 is 6427162412.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (35).

It is a self number, because there is not a number n which added to its sum of digits gives 21426172460.

It is not an unprimeable number, because it can be changed into a prime (21426172463) 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, 3071897 + ... + 3078863.

It is an arithmetic number, because the mean of its divisors is an integer number (584726688).

Almost surely, 2^21426172460 is an apocalyptic number.

21426172460 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 21426172460, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28066881024).

21426172460 is an abundant number, since it is smaller than the sum of its proper divisors (34707589588).

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

21426172460 is a wasteful number, since it uses less digits than its factorization.

21426172460 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8991 (or 8989 counting only the distinct ones).

The product of its (nonzero) digits is 32256, while the sum is 35.

The spelling of 21426172460 in words is "twenty-one billion, four hundred twenty-six million, one hundred seventy-two thousand, four hundred sixty".