21049742 has 16 divisors (see below), whose sum is σ = 36372480. Its totient is φ = 8949528.

The previous prime is 21049729. The next prime is 21049759. The reversal of 21049742 is 24794012.

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, 4142 + ... + 7697.

It is an arithmetic number, because the mean of its divisors is an integer number (2273280).

Almost surely, 2^21049742 is an apocalyptic number.

21049742 is a deficient number, since it is larger than the sum of its proper divisors (15322738).

21049742 is a wasteful number, since it uses less digits than its factorization.

21049742 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11975.

The product of its (nonzero) digits is 4032, while the sum is 29.

The square root of 21049742 is about 4587.9997820401. Note that the first 3 decimals coincide. The cubic root of 21049742 is about 276.1100782644.

The spelling of 21049742 in words is "twenty-one million, forty-nine thousand, seven hundred forty-two".