19813972 has 6 divisors (see below), whose sum is σ = 34674458. Its totient is φ = 9906984.

The previous prime is 19813967. The next prime is 19813987. The reversal of 19813972 is 27931891.

It can be written as a sum of positive squares in only one way, i.e., 16112196 + 3701776 = 4014^2 + 1924^2 .

It is a super-3 number, since 3×19813972³ (a number of 23 digits) contains 333 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2476743 + ... + 2476750.

Almost surely, 2^19813972 is an apocalyptic number.

It is an amenable number.

19813972 is a deficient number, since it is larger than the sum of its proper divisors (14860486).

19813972 is a wasteful number, since it uses less digits than its factorization.

19813972 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4953497 (or 4953495 counting only the distinct ones).

The product of its digits is 27216, while the sum is 40.

The square root of 19813972 is about 4451.2888021336. The cubic root of 19813972 is about 270.5975426170.

The spelling of 19813972 in words is "nineteen million, eight hundred thirteen thousand, nine hundred seventy-two".