19961240 has 64 divisors (see below), whose sum is σ = 50500800. Its totient is φ = 7045632.

The previous prime is 19961237. The next prime is 19961257. The reversal of 19961240 is 4216991.

It is a super-2 number, since 2×19961240² = 796902204675200, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 19961197 and 19961206.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11126 + ... + 12794.

It is an arithmetic number, because the mean of its divisors is an integer number (789075).

Almost surely, 2^19961240 is an apocalyptic number.

19961240 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 19961240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25250400).

19961240 is an abundant number, since it is smaller than the sum of its proper divisors (30539560).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

19961240 is a wasteful number, since it uses less digits than its factorization.

19961240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1716 (or 1712 counting only the distinct ones).

The product of its (nonzero) digits is 3888, while the sum is 32.

The square root of 19961240 is about 4467.8003536416. The cubic root of 19961240 is about 271.2662968823.

The spelling of 19961240 in words is "nineteen million, nine hundred sixty-one thousand, two hundred forty".