21577142 has 16 divisors (see below), whose sum is σ = 34018512. Its totient is φ = 10251360.

The previous prime is 21577133. The next prime is 21577163. The reversal of 21577142 is 24177512.

It is a plaindrome in base 8.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 209 + ... + 6572.

It is an arithmetic number, because the mean of its divisors is an integer number (2126157).

Almost surely, 2^21577142 is an apocalyptic number.

21577142 is a deficient number, since it is larger than the sum of its proper divisors (12441370).

21577142 is a wasteful number, since it uses less digits than its factorization.

21577142 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6863.

The product of its digits is 3920, while the sum is 29.

The square root of 21577142 is about 4645.1202352576. The cubic root of 21577142 is about 278.3970569750.

The spelling of 21577142 in words is "twenty-one million, five hundred seventy-seven thousand, one hundred forty-two".