21476947 has 2 divisors, whose sum is σ = 21476948. Its totient is φ = 21476946.

The previous prime is 21476927. The next prime is 21476951. The reversal of 21476947 is 74967412.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21476947 is a prime.

It is a super-2 number, since 2×21476947² = 922518504881618, which contains 22 as substring.

It is an alternating number because its digits alternate between even and odd.

It is not a weakly prime, because it can be changed into another prime (21476927) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10738473 + 10738474.

It is an arithmetic number, because the mean of its divisors is an integer number (10738474).

Almost surely, 2^21476947 is an apocalyptic number.

21476947 is a deficient number, since it is larger than the sum of its proper divisors (1).

21476947 is an equidigital number, since it uses as much as digits as its factorization.

21476947 is an evil number, because the sum of its binary digits is even.

The product of its digits is 84672, while the sum is 40.

The square root of 21476947 is about 4634.3227121123. The cubic root of 21476947 is about 277.9654693753.

The spelling of 21476947 in words is "twenty-one million, four hundred seventy-six thousand, nine hundred forty-seven".