21157054 has 8 divisors (see below), whose sum is σ = 31790880. Its totient is φ = 10560096.

The previous prime is 21157049. The next prime is 21157067. The reversal of 21157054 is 45075112.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 7734 + ... + 10105.

It is an arithmetic number, because the mean of its divisors is an integer number (3973860).

Almost surely, 2^21157054 is an apocalyptic number.

21157054 is a deficient number, since it is larger than the sum of its proper divisors (10633826).

21157054 is a wasteful number, since it uses less digits than its factorization.

21157054 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18434.

The product of its (nonzero) digits is 1400, while the sum is 25.

The square root of 21157054 is about 4599.6797714624. The cubic root of 21157054 is about 276.5784880518.

The spelling of 21157054 in words is "twenty-one million, one hundred fifty-seven thousand, fifty-four".