21201078 has 32 divisors (see below), whose sum is σ = 44925696. Its totient is φ = 6655968.

The previous prime is 21201067. The next prime is 21201079. The reversal of 21201078 is 87010212.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21201079) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8100 + ... + 10392.

It is an arithmetic number, because the mean of its divisors is an integer number (1403928).

Almost surely, 2^21201078 is an apocalyptic number.

21201078 is an abundant number, since it is smaller than the sum of its proper divisors (23724618).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21201078 is a wasteful number, since it uses less digits than its factorization.

21201078 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2388.

The product of its (nonzero) digits is 224, while the sum is 21.

The square root of 21201078 is about 4604.4628351199. The cubic root of 21201078 is about 276.7701917376.

The spelling of 21201078 in words is "twenty-one million, two hundred one thousand, seventy-eight".