21077429 has 4 divisors (see below), whose sum is σ = 21195360. Its totient is φ = 20959500.

The previous prime is 21077401. The next prime is 21077431. The reversal of 21077429 is 92477012.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21077429 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21077395 and 21077404.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21077449) 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 3 ways as a sum of consecutive naturals, for example, 58697 + ... + 59054.

It is an arithmetic number, because the mean of its divisors is an integer number (5298840).

Almost surely, 2^21077429 is an apocalyptic number.

It is an amenable number.

21077429 is a deficient number, since it is larger than the sum of its proper divisors (117931).

21077429 is a wasteful number, since it uses less digits than its factorization.

21077429 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 117930.

The product of its (nonzero) digits is 7056, while the sum is 32.

The square root of 21077429 is about 4591.0161184644. The cubic root of 21077429 is about 276.2310822887.

The spelling of 21077429 in words is "twenty-one million, seventy-seven thousand, four hundred twenty-nine".