21673412 has 6 divisors (see below), whose sum is σ = 37928478. Its totient is φ = 10836704.

The previous prime is 21673409. The next prime is 21673423. The reversal of 21673412 is 21437612.

It can be written as a sum of positive squares in only one way, i.e., 19061956 + 2611456 = 4366^2 + 1616^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2709173 + ... + 2709180.

It is an arithmetic number, because the mean of its divisors is an integer number (6321413).

Almost surely, 2^21673412 is an apocalyptic number.

It is an amenable number.

21673412 is a deficient number, since it is larger than the sum of its proper divisors (16255066).

21673412 is a wasteful number, since it uses less digits than its factorization.

21673412 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5418357 (or 5418355 counting only the distinct ones).

The product of its digits is 2016, while the sum is 26.

The square root of 21673412 is about 4655.4711899012. The cubic root of 21673412 is about 278.8104809543.

The spelling of 21673412 in words is "twenty-one million, six hundred seventy-three thousand, four hundred twelve".