21078701 has 16 divisors (see below), whose sum is σ = 24944640. Its totient is φ = 17437680.

The previous prime is 21078637. The next prime is 21078703. The reversal of 21078701 is 10787012.

It is a cyclic number.

It is not a de Polignac number, because 21078701 - 2⁶ = 21078637 is a prime.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21078703) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 25586 + ... + 26396.

It is an arithmetic number, because the mean of its divisors is an integer number (1559040).

Almost surely, 2^21078701 is an apocalyptic number.

It is an amenable number.

21078701 is a deficient number, since it is larger than the sum of its proper divisors (3865939).

21078701 is an equidigital number, since it uses as much as digits as its factorization.

21078701 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 944.

The product of its (nonzero) digits is 784, while the sum is 26.

The square root of 21078701 is about 4591.1546477983. The cubic root of 21078701 is about 276.2366389257.

The spelling of 21078701 in words is "twenty-one million, seventy-eight thousand, seven hundred one".