20695690 has 8 divisors (see below), whose sum is σ = 37252260. Its totient is φ = 8278272.

The previous prime is 20695679. The next prime is 20695711. The reversal of 20695690 is 9659602.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 19456921 + 1238769 = 4411^2 + 1113^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-3 number, since 3×20695690³ (a number of 23 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1034775 + ... + 1034794.

Almost surely, 2^20695690 is an apocalyptic number.

20695690 is a deficient number, since it is larger than the sum of its proper divisors (16556570).

20695690 is a wasteful number, since it uses less digits than its factorization.

20695690 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2069576.

The product of its (nonzero) digits is 29160, while the sum is 37.

The square root of 20695690 is about 4549.2515867997. The cubic root of 20695690 is about 274.5532802351.

It can be divided in two parts, 206956 and 90, that added together give a triangular number (207046 = T₆₄₃).

The spelling of 20695690 in words is "twenty million, six hundred ninety-five thousand, six hundred ninety".