21434699520 has 1152 divisors, whose sum is σ = 90106060800. Its totient is φ = 4837294080.

The previous prime is 21434699497. The next prime is 21434699527. The reversal of 21434699520 is 2599643412.

21434699520 is a `hidden beast` number, since 2 + 1 + 4 + 34 + 6 + 99 + 520 = 666.

It is a tau number, because it is divible by the number of its divisors (1152).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21434699527) by changing a digit.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 691441905 + ... + 691441935.

Almost surely, 2^21434699520 is an apocalyptic number.

21434699520 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 21434699520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (45053030400).

21434699520 is an abundant number, since it is smaller than the sum of its proper divisors (68671361280).

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

21434699520 is an equidigital number, since it uses as much as digits as its factorization.

21434699520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 105 (or 73 counting only the distinct ones).

The product of its (nonzero) digits is 466560, while the sum is 45.

The spelling of 21434699520 in words is "twenty-one billion, four hundred thirty-four million, six hundred ninety-nine thousand, five hundred twenty".