21275442 has 12 divisors (see below), whose sum is σ = 46096830. Its totient is φ = 7091808.

The previous prime is 21275399. The next prime is 21275461. The reversal of 21275442 is 24457212.

21275442 is a `hidden beast` number, since 212 + 7 + 5 + 442 = 666.

It can be written as a sum of positive squares in only one way, i.e., 11029041 + 10246401 = 3321^2 + 3201^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 590967 + ... + 591002.

Almost surely, 2^21275442 is an apocalyptic number.

21275442 is an abundant number, since it is smaller than the sum of its proper divisors (24821388).

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

21275442 is a wasteful number, since it uses less digits than its factorization.

21275442 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1181977 (or 1181974 counting only the distinct ones).

The product of its digits is 4480, while the sum is 27.

The square root of 21275442 is about 4612.5309755057. The cubic root of 21275442 is about 277.0934099161.

It can be divided in two parts, 2127 and 5442, that added together give a square (7569 = 87²).

The spelling of 21275442 in words is "twenty-one million, two hundred seventy-five thousand, four hundred forty-two".