19221957 has 6 divisors (see below), whose sum is σ = 27765062. Its totient is φ = 12814632.

The previous prime is 19221949. The next prime is 19221959. The reversal of 19221957 is 75912291.

It can be written as a sum of positive squares in only one way, i.e., 12916836 + 6305121 = 3594^2 + 2511^2 .

It is not a de Polignac number, because 19221957 - 2³ = 19221949 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19221959) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1067878 + ... + 1067895.

Almost surely, 2^19221957 is an apocalyptic number.

It is an amenable number.

19221957 is a deficient number, since it is larger than the sum of its proper divisors (8543105).

19221957 is a wasteful number, since it uses less digits than its factorization.

19221957 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2135779 (or 2135776 counting only the distinct ones).

The product of its digits is 11340, while the sum is 36.

The square root of 19221957 is about 4384.2852325094. The cubic root of 19221957 is about 267.8752157253.

The spelling of 19221957 in words is "nineteen million, two hundred twenty-one thousand, nine hundred fifty-seven".