21409377570 has 128 divisors (see below), whose sum is σ = 65400814080. Its totient is φ = 4882083840.

The previous prime is 21409377551. The next prime is 21409377643. The reversal of 21409377570 is 7577390412.

21409377570 is a `hidden beast` number, since 2 + 1 + 4 + 0 + 9 + 3 + 77 + 570 = 666.

It is a super-2 number, since 2×21409377570² (a number of 21 digits) contains 22 as substring.

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

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 805290 + ... + 831450.

It is an arithmetic number, because the mean of its divisors is an integer number (510943860).

Almost surely, 2^21409377570 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21409377570, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32700407040).

21409377570 is an abundant number, since it is smaller than the sum of its proper divisors (43991436510).

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

21409377570 is a wasteful number, since it uses less digits than its factorization.

21409377570 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26617 (or 26611 counting only the distinct ones).

The product of its (nonzero) digits is 370440, while the sum is 45.

The spelling of 21409377570 in words is "twenty-one billion, four hundred nine million, three hundred seventy-seven thousand, five hundred seventy".