21130074 has 36 divisors (see below), whose sum is σ = 53258634. Its totient is φ = 6036912.

The previous prime is 21130073. The next prime is 21130079. The reversal of 21130074 is 47003112.

It can be written as a sum of positive squares in only one way, i.e., 15093225 + 6036849 = 3885^2 + 2457^2 .

It is a Harshad number since it is a multiple of its sum of digits (18).

It is not an unprimeable number, because it can be changed into a prime (21130073) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 11097 + ... + 12860.

Almost surely, 2^21130074 is an apocalyptic number.

21130074 is an abundant number, since it is smaller than the sum of its proper divisors (32128560).

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

21130074 is a wasteful number, since it uses less digits than its factorization.

21130074 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23979 (or 23969 counting only the distinct ones).

The product of its (nonzero) digits is 168, while the sum is 18.

The square root of 21130074 is about 4596.7460230037. The cubic root of 21130074 is about 276.4608714592.

Adding to 21130074 its reverse (47003112), we get a palindrome (68133186).

The spelling of 21130074 in words is "twenty-one million, one hundred thirty thousand, seventy-four".