20695581 has 16 divisors (see below), whose sum is σ = 31041920. Its totient is φ = 13795596.

The previous prime is 20695559. The next prime is 20695601. The reversal of 20695581 is 18559602.

It is a happy number.

It is not a de Polignac number, because 20695581 - 2⁶ = 20695517 is a prime.

It is a super-2 number, since 2×20695581² = 856614145855122, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20696581) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2545 + ... + 6918.

It is an arithmetic number, because the mean of its divisors is an integer number (1940120).

Almost surely, 2^20695581 is an apocalyptic number.

It is an amenable number.

20695581 is a deficient number, since it is larger than the sum of its proper divisors (10346339).

20695581 is an frugal number, since it uses more digits than its factorization.

20695581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9484 (or 9466 counting only the distinct ones).

The product of its (nonzero) digits is 21600, while the sum is 36.

The square root of 20695581 is about 4549.2396067914. The cubic root of 20695581 is about 274.5527982288.

The spelling of 20695581 in words is "twenty million, six hundred ninety-five thousand, five hundred eighty-one".