21146667520 has 160 divisors (see below), whose sum is σ = 55531910016. Its totient is φ = 7659110400.

The previous prime is 21146667431. The next prime is 21146667527. The reversal of 21146667520 is 2576664112.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (160).

It is a Harshad number since it is a multiple of its sum of digits (40).

It is not an unprimeable number, because it can be changed into a prime (21146667527) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7798965 + ... + 7801675.

Almost surely, 2^21146667520 is an apocalyptic number.

21146667520 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 21146667520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27765955008).

21146667520 is an abundant number, since it is smaller than the sum of its proper divisors (34385242496).

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

21146667520 is a wasteful number, since it uses less digits than its factorization.

21146667520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3022 (or 3006 counting only the distinct ones).

The product of its (nonzero) digits is 120960, while the sum is 40.

The spelling of 21146667520 in words is "twenty-one billion, one hundred forty-six million, six hundred sixty-seven thousand, five hundred twenty".