19925661 has 16 divisors (see below), whose sum is σ = 31961600. Its totient is φ = 10786608.

The previous prime is 19925627. The next prime is 19925677. The reversal of 19925661 is 16652991.

It is not a de Polignac number, because 19925661 - 2⁶ = 19925597 is a prime.

It is a super-3 number, since 3×19925661³ (a number of 23 digits) contains 333 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19925611) 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, 24571 + ... + 25368.

It is an arithmetic number, because the mean of its divisors is an integer number (1997600).

Almost surely, 2^19925661 is an apocalyptic number.

It is an amenable number.

19925661 is a deficient number, since it is larger than the sum of its proper divisors (12035939).

19925661 is a wasteful number, since it uses less digits than its factorization.

19925661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 49968.

The product of its digits is 29160, while the sum is 39.

The square root of 19925661 is about 4463.8168645230. The cubic root of 19925661 is about 271.1050322935.

The spelling of 19925661 in words is "nineteen million, nine hundred twenty-five thousand, six hundred sixty-one".