21378701 has 2 divisors, whose sum is σ = 21378702. Its totient is φ = 21378700.

The previous prime is 21378691. The next prime is 21378733. The reversal of 21378701 is 10787312.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18913801 + 2464900 = 4349^2 + 1570^2 .

It is a cyclic number.

It is not a de Polignac number, because 21378701 - 2¹⁰ = 21377677 is a prime.

It is a super-3 number, since 3×21378701³ (a number of 23 digits) contains 333 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21378751) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10689350 + 10689351.

It is an arithmetic number, because the mean of its divisors is an integer number (10689351).

Almost surely, 2^21378701 is an apocalyptic number.

It is an amenable number.

21378701 is a deficient number, since it is larger than the sum of its proper divisors (1).

21378701 is an equidigital number, since it uses as much as digits as its factorization.

21378701 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2352, while the sum is 29.

The square root of 21378701 is about 4623.7107392223. The cubic root of 21378701 is about 277.5409716849.

The spelling of 21378701 in words is "twenty-one million, three hundred seventy-eight thousand, seven hundred one".