21435057 has 32 divisors (see below), whose sum is σ = 37877760. Its totient is φ = 11713680.

The previous prime is 21435049. The next prime is 21435061. The reversal of 21435057 is 75053412.

It is a happy number.

It is not a de Polignac number, because 21435057 - 2³ = 21435049 is a prime.

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

It is a self number, because there is not a number n which added to its sum of digits gives 21435057.

It is not an unprimeable number, because it can be changed into a prime (21435017) by changing a digit.

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 31 ways as a sum of consecutive naturals, for example, 1882 + ... + 6812.

It is an arithmetic number, because the mean of its divisors is an integer number (1183680).

Almost surely, 2^21435057 is an apocalyptic number.

21435057 is a gapful number since it is divisible by the number (27) formed by its first and last digit.

It is an amenable number.

21435057 is a deficient number, since it is larger than the sum of its proper divisors (16442703).

21435057 is a wasteful number, since it uses less digits than its factorization.

21435057 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4970 (or 4964 counting only the distinct ones).

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

The square root of 21435057 is about 4629.8009676443. The cubic root of 21435057 is about 277.7846312561.

Adding to 21435057 its reverse (75053412), we get a palindrome (96488469).

The spelling of 21435057 in words is "twenty-one million, four hundred thirty-five thousand, fifty-seven".