21541534 has 16 divisors (see below), whose sum is σ = 37136736. Its totient is φ = 9180000.

The previous prime is 21541517. The next prime is 21541537. The reversal of 21541534 is 43514512.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 21541499 and 21541508.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21541537) 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, 1717 + ... + 6784.

It is an arithmetic number, because the mean of its divisors is an integer number (2321046).

Almost surely, 2^21541534 is an apocalyptic number.

21541534 is a deficient number, since it is larger than the sum of its proper divisors (15595202).

21541534 is a wasteful number, since it uses less digits than its factorization.

21541534 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8691.

The product of its digits is 2400, while the sum is 25.

The square root of 21541534 is about 4641.2858132203. The cubic root of 21541534 is about 278.2438296921.

The spelling of 21541534 in words is "twenty-one million, five hundred forty-one thousand, five hundred thirty-four".