21257054 has 16 divisors (see below), whose sum is σ = 39244128. Its totient is φ = 8409312.

The previous prime is 21257053. The next prime is 21257059. The reversal of 21257054 is 45075212.

It is a super-4 number, since 4×21257054⁴ (a number of 30 digits) contains 4444 as substring.

It is a Harshad number since it is a multiple of its sum of digits (26).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21257053) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 58217 + ... + 58580.

It is an arithmetic number, because the mean of its divisors is an integer number (2452758).

Almost surely, 2^21257054 is an apocalyptic number.

21257054 is a deficient number, since it is larger than the sum of its proper divisors (17987074).

21257054 is a wasteful number, since it uses less digits than its factorization.

21257054 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 116819.

The product of its (nonzero) digits is 2800, while the sum is 26.

The square root of 21257054 is about 4610.5372788863. The cubic root of 21257054 is about 277.0135578779.

The spelling of 21257054 in words is "twenty-one million, two hundred fifty-seven thousand, fifty-four".