21470077 has 8 divisors (see below), whose sum is σ = 21785400. Its totient is φ = 21156864.

The previous prime is 21470069. The next prime is 21470081. The reversal of 21470077 is 77007412.

It can be written as a sum of positive squares in 4 ways, for example, as 42436 + 21427641 = 206^2 + 4629^2 .

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

It is not a de Polignac number, because 21470077 - 2³ = 21470069 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21470047) 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, 37449 + ... + 38017.

It is an arithmetic number, because the mean of its divisors is an integer number (2723175).

Almost surely, 2^21470077 is an apocalyptic number.

It is an amenable number.

21470077 is a deficient number, since it is larger than the sum of its proper divisors (315323).

21470077 is an equidigital number, since it uses as much as digits as its factorization.

21470077 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1055.

The product of its (nonzero) digits is 2744, while the sum is 28.

The square root of 21470077 is about 4633.5814441963. The cubic root of 21470077 is about 277.9358278807.

Adding to 21470077 its reverse (77007412), we get a palindrome (98477489).

The spelling of 21470077 in words is "twenty-one million, four hundred seventy thousand, seventy-seven".