21472690 has 8 divisors (see below), whose sum is σ = 38650860. Its totient is φ = 8589072.

The previous prime is 21472687. The next prime is 21472699. The reversal of 21472690 is 9627412.

It can be written as a sum of positive squares in 2 ways, for example, as 19509889 + 1962801 = 4417^2 + 1401^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×21472690² = 922152831672200, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21472699) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1073625 + ... + 1073644.

Almost surely, 2^21472690 is an apocalyptic number.

21472690 is a deficient number, since it is larger than the sum of its proper divisors (17178170).

21472690 is a wasteful number, since it uses less digits than its factorization.

21472690 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2147276.

The product of its (nonzero) digits is 6048, while the sum is 31.

The square root of 21472690 is about 4633.8633989361. The cubic root of 21472690 is about 277.9471027488.

The spelling of 21472690 in words is "twenty-one million, four hundred seventy-two thousand, six hundred ninety".