21001420146 has 32 divisors (see below), whose sum is σ = 49551740928. Its totient is φ = 5806843920.

The previous prime is 21001420133. The next prime is 21001420147. The reversal of 21001420146 is 64102410012.

It is a happy number.

It is a super-2 number, since 2×21001420146² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is not an unprimeable number, because it can be changed into a prime (21001420147) 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, 8063760 + ... + 8066363.

It is an arithmetic number, because the mean of its divisors is an integer number (1548491904).

Almost surely, 2^21001420146 is an apocalyptic number.

21001420146 is an abundant number, since it is smaller than the sum of its proper divisors (28550320782).

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

21001420146 is a wasteful number, since it uses less digits than its factorization.

21001420146 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16130166.

The product of its (nonzero) digits is 384, while the sum is 21.

Adding to 21001420146 its reverse (64102410012), we get a palindrome (85103830158).

The spelling of 21001420146 in words is "twenty-one billion, one million, four hundred twenty thousand, one hundred forty-six".