21057354 has 32 divisors (see below), whose sum is σ = 47940480. Its totient is φ = 6847200.

The previous prime is 21057341. The next prime is 21057419. The reversal of 21057354 is 45375012.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2542 + ... + 6969.

It is an arithmetic number, because the mean of its divisors is an integer number (1498140).

Almost surely, 2^21057354 is an apocalyptic number.

21057354 is an abundant number, since it is smaller than the sum of its proper divisors (26883126).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21057354 is a wasteful number, since it uses less digits than its factorization.

21057354 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9563 (or 9557 counting only the distinct ones).

The product of its (nonzero) digits is 4200, while the sum is 27.

The square root of 21057354 is about 4588.8292624590. The cubic root of 21057354 is about 276.1433565285.

The spelling of 21057354 in words is "twenty-one million, fifty-seven thousand, three hundred fifty-four".