21387175316 has 48 divisors (see below), whose sum is σ = 41876125200. Its totient is φ = 9489564672.

The previous prime is 21387175309. The next prime is 21387175319. The reversal of 21387175316 is 61357178312.

It can be written as a sum of positive squares in 8 ways, for example, as 982195600 + 20404979716 = 31340^2 + 142846^2 .

It is a super-2 number, since 2×21387175316² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21387175319) 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, 320930 + ... + 381798.

It is an arithmetic number, because the mean of its divisors is an integer number (872419275).

Almost surely, 2^21387175316 is an apocalyptic number.

21387175316 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is an amenable number.

21387175316 is a deficient number, since it is larger than the sum of its proper divisors (20488949884).

21387175316 is a wasteful number, since it uses less digits than its factorization.

21387175316 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 61148 (or 61146 counting only the distinct ones).

The product of its digits is 211680, while the sum is 44.

The spelling of 21387175316 in words is "twenty-one billion, three hundred eighty-seven million, one hundred seventy-five thousand, three hundred sixteen".