21011662340 has 12 divisors (see below), whose sum is σ = 44124490956. Its totient is φ = 8404664928.

The previous prime is 21011662333. The next prime is 21011662369. The reversal of 21011662340 is 4326611012.

It can be written as a sum of positive squares in 2 ways, for example, as 16462429636 + 4549232704 = 128306^2 + 67448^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 525291539 + ... + 525291578.

It is an arithmetic number, because the mean of its divisors is an integer number (3677040913).

Almost surely, 2^21011662340 is an apocalyptic number.

21011662340 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21011662340 is an abundant number, since it is smaller than the sum of its proper divisors (23112828616).

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

21011662340 is a wasteful number, since it uses less digits than its factorization.

21011662340 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1050583126 (or 1050583124 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 26.

The spelling of 21011662340 in words is "twenty-one billion, eleven million, six hundred sixty-two thousand, three hundred forty".