21577340 has 24 divisors (see below), whose sum is σ = 45936240. Its totient is φ = 8512128.

The previous prime is 21577319. The next prime is 21577343. The reversal of 21577340 is 4377512.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21577343) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5930 + ... + 8849.

It is an arithmetic number, because the mean of its divisors is an integer number (1914010).

Almost surely, 2^21577340 is an apocalyptic number.

21577340 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21577340 is an abundant number, since it is smaller than the sum of its proper divisors (24358900).

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

21577340 is a wasteful number, since it uses less digits than its factorization.

21577340 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14861 (or 14859 counting only the distinct ones).

The product of its (nonzero) digits is 5880, while the sum is 29.

The square root of 21577340 is about 4645.1415478971. The cubic root of 21577340 is about 278.3979085312.

The spelling of 21577340 in words is "twenty-one million, five hundred seventy-seven thousand, three hundred forty".