20521474 has 16 divisors (see below), whose sum is σ = 32219712. Its totient is φ = 9784368.

The previous prime is 20521453. The next prime is 20521489. The reversal of 20521474 is 47412502.

It is a super-2 number, since 2×20521474² = 842261790265352, which contains 22 as substring.

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, 23632 + ... + 24484.

It is an arithmetic number, because the mean of its divisors is an integer number (2013732).

Almost surely, 2^20521474 is an apocalyptic number.

20521474 is a deficient number, since it is larger than the sum of its proper divisors (11698238).

20521474 is a wasteful number, since it uses less digits than its factorization.

20521474 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1401.

The product of its (nonzero) digits is 2240, while the sum is 25.

The square root of 20521474 is about 4530.0633549654. The cubic root of 20521474 is about 273.7807132474.

Adding to 20521474 its reverse (47412502), we get a palindrome (67933976).

The spelling of 20521474 in words is "twenty million, five hundred twenty-one thousand, four hundred seventy-four".