19102421 has 8 divisors (see below), whose sum is σ = 20854680. Its totient is φ = 17390592.

The previous prime is 19102379. The next prime is 19102423. The reversal of 19102421 is 12420191.

It can be written as a sum of positive squares in 4 ways, for example, as 3783025 + 15319396 = 1945^2 + 3914^2 .

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-19102421 is a prime.

It is a super-2 number, since 2×19102421² = 729804976122482, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 19102393 and 19102402.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19102423) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9116 + ... + 11013.

It is an arithmetic number, because the mean of its divisors is an integer number (2606835).

Almost surely, 2^19102421 is an apocalyptic number.

It is an amenable number.

19102421 is a deficient number, since it is larger than the sum of its proper divisors (1752259).

19102421 is a wasteful number, since it uses less digits than its factorization.

19102421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20215.

The product of its (nonzero) digits is 144, while the sum is 20.

The square root of 19102421 is about 4370.6316477141. The cubic root of 19102421 is about 267.3187802201.

The spelling of 19102421 in words is "nineteen million, one hundred two thousand, four hundred twenty-one".