21454690 has 8 divisors (see below), whose sum is σ = 38618460. Its totient is φ = 8581872.

The previous prime is 21454687. The next prime is 21454711. The reversal of 21454690 is 9645412.

It can be written as a sum of positive squares in 2 ways, for example, as 18601969 + 2852721 = 4313^2 + 1689^2 .

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

It is a super-2 number, since 2×21454690² = 920607445992200, which contains 22 as substring.

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, 1072725 + ... + 1072744.

Almost surely, 2^21454690 is an apocalyptic number.

21454690 is a deficient number, since it is larger than the sum of its proper divisors (17163770).

21454690 is a wasteful number, since it uses less digits than its factorization.

21454690 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2145476.

The product of its (nonzero) digits is 8640, while the sum is 31.

The square root of 21454690 is about 4631.9207678888. The cubic root of 21454690 is about 277.8694157508.

The spelling of 21454690 in words is "twenty-one million, four hundred fifty-four thousand, six hundred ninety".