21965019 has 16 divisors (see below), whose sum is σ = 30382080. Its totient is φ = 14100480.

The previous prime is 21965017. The next prime is 21965029. The reversal of 21965019 is 91056912.

It is not a de Polignac number, because 21965019 - 2¹ = 21965017 is a prime.

It is a super-2 number, since 2×21965019² = 964924119340722, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21965017) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 23442 + ... + 24360.

It is an arithmetic number, because the mean of its divisors is an integer number (1898880).

Almost surely, 2^21965019 is an apocalyptic number.

21965019 is a deficient number, since it is larger than the sum of its proper divisors (8417061).

21965019 is a wasteful number, since it uses less digits than its factorization.

21965019 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1210.

The product of its (nonzero) digits is 4860, while the sum is 33.

The square root of 21965019 is about 4686.6852891996. The cubic root of 21965019 is about 280.0553419521.

The spelling of 21965019 in words is "twenty-one million, nine hundred sixty-five thousand, nineteen".