21501002420 has 48 divisors (see below), whose sum is σ = 46080171648. Its totient is φ = 8425173120.

The previous prime is 21501002333. The next prime is 21501002437. The reversal of 21501002420 is 2420010512.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 174719 + ... + 271161.

It is an arithmetic number, because the mean of its divisors is an integer number (960003576).

Almost surely, 2^21501002420 is an apocalyptic number.

21501002420 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21501002420 is an abundant number, since it is smaller than the sum of its proper divisors (24579169228).

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

21501002420 is a wasteful number, since it uses less digits than its factorization.

21501002420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 96680 (or 96678 counting only the distinct ones).

The product of its (nonzero) digits is 160, while the sum is 17.

Adding to 21501002420 its reverse (2420010512), we get a palindrome (23921012932).

The spelling of 21501002420 in words is "twenty-one billion, five hundred one million, two thousand, four hundred twenty".