21430977 has 8 divisors (see below), whose sum is σ = 28764480. Its totient is φ = 14192400.

The previous prime is 21430957. The next prime is 21430979. The reversal of 21430977 is 77903412.

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

It is not a de Polignac number, because 21430977 - 2¹¹ = 21428929 is a prime.

It is a Smith number, since the sum of its digits (33) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (21430979) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 23202 + ... + 24107.

It is an arithmetic number, because the mean of its divisors is an integer number (3595560).

Almost surely, 2^21430977 is an apocalyptic number.

It is an amenable number.

21430977 is a deficient number, since it is larger than the sum of its proper divisors (7333503).

21430977 is a wasteful number, since it uses less digits than its factorization.

21430977 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 47463.

The product of its (nonzero) digits is 10584, while the sum is 33.

The square root of 21430977 is about 4629.3603229820. The cubic root of 21430977 is about 277.7670054074.

The spelling of 21430977 in words is "twenty-one million, four hundred thirty thousand, nine hundred seventy-seven".