21061270 has 16 divisors (see below), whose sum is σ = 38106288. Its totient is φ = 8380960.

The previous prime is 21061259. The next prime is 21061309. The reversal of 21061270 is 7216012.

21061270 = T₂₉₀₀ + T₂₉₀₁ + ... + T₂₉₀₄.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3376 + ... + 7315.

It is an arithmetic number, because the mean of its divisors is an integer number (2381643).

Almost surely, 2^21061270 is an apocalyptic number.

21061270 is a deficient number, since it is larger than the sum of its proper divisors (17045018).

21061270 is a wasteful number, since it uses less digits than its factorization.

21061270 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10895.

The product of its (nonzero) digits is 168, while the sum is 19.

The square root of 21061270 is about 4589.2559309762. The cubic root of 21061270 is about 276.1604734363.

Adding to 21061270 its reverse (7216012), we get a palindrome (28277282).

The spelling of 21061270 in words is "twenty-one million, sixty-one thousand, two hundred seventy".