21700371 has 16 divisors (see below), whose sum is σ = 36073728. Its totient is φ = 11272800.

The previous prime is 21700351. The next prime is 21700379. The reversal of 21700371 is 17300712.

It is not a de Polignac number, because 21700371 - 2⁷ = 21700243 is a prime.

It is a super-2 number, since 2×21700371² = 941812203075282, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is not an unprimeable number, because it can be changed into a prime (21700379) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 46740 + ... + 47201.

It is an arithmetic number, because the mean of its divisors is an integer number (2254608).

Almost surely, 2^21700371 is an apocalyptic number.

21700371 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

21700371 is a deficient number, since it is larger than the sum of its proper divisors (14373357).

21700371 is a wasteful number, since it uses less digits than its factorization.

21700371 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 93962.

The product of its (nonzero) digits is 294, while the sum is 21.

The square root of 21700371 is about 4658.3657005435. The cubic root of 21700371 is about 278.9260347859.

The spelling of 21700371 in words is "twenty-one million, seven hundred thousand, three hundred seventy-one".