21400757 has 8 divisors (see below), whose sum is σ = 25247232. Its totient is φ = 17751600.

The previous prime is 21400751. The next prime is 21400781. The reversal of 21400757 is 75700412.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21400757 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 (21400751) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 49094 + ... + 49527.

It is an arithmetic number, because the mean of its divisors is an integer number (3155904).

Almost surely, 2^21400757 is an apocalyptic number.

It is an amenable number.

21400757 is a deficient number, since it is larger than the sum of its proper divisors (3846475).

21400757 is an equidigital number, since it uses as much as digits as its factorization.

21400757 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 98659.

The product of its (nonzero) digits is 1960, while the sum is 26.

The square root of 21400757 is about 4626.0952216745. The cubic root of 21400757 is about 277.6363834649.

The spelling of 21400757 in words is "twenty-one million, four hundred thousand, seven hundred fifty-seven".