221015001620 has 48 divisors (see below), whose sum is σ = 530824492800. Its totient is φ = 75721073664.

The previous prime is 221015001583. The next prime is 221015001659. The reversal of 221015001620 is 26100510122.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a junction number, because it is equal to n+sod(n) for n = 221015001592 and 221015001601.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 386045 + ... + 768804.

It is an arithmetic number, because the mean of its divisors is an integer number (11058843600).

Almost surely, 2^221015001620 is an apocalyptic number.

221015001620 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

221015001620 is an abundant number, since it is smaller than the sum of its proper divisors (309809491180).

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

221015001620 is a wasteful number, since it uses less digits than its factorization.

221015001620 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1156232 (or 1156230 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 20.

Adding to 221015001620 its reverse (26100510122), we get a palindrome (247115511742).

The spelling of 221015001620 in words is "two hundred twenty-one billion, fifteen million, one thousand, six hundred twenty".