19685961 has 24 divisors (see below), whose sum is σ = 30161664. Its totient is φ = 12350880.

The previous prime is 19685951. The next prime is 19685969. The reversal of 19685961 is 16958691.

19685961 = T₁₀₁₃ + T₁₀₁₄ + ... + T₁₀₄₉.

It is not a de Polignac number, because 19685961 - 2⁵ = 19685929 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (19685969) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 9370 + ... + 11276.

It is an arithmetic number, because the mean of its divisors is an integer number (1256736).

Almost surely, 2^19685961 is an apocalyptic number.

It is an amenable number.

19685961 is a deficient number, since it is larger than the sum of its proper divisors (10475703).

19685961 is a wasteful number, since it uses less digits than its factorization.

19685961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1981 (or 1978 counting only the distinct ones).

The product of its digits is 116640, while the sum is 45.

The square root of 19685961 is about 4436.8864082823. The cubic root of 19685961 is about 270.0135384158.

The spelling of 19685961 in words is "nineteen million, six hundred eighty-five thousand, nine hundred sixty-one".