21475200787 has 4 divisors (see below), whose sum is σ = 21475499920. Its totient is φ = 21474901656.

The previous prime is 21475200781. The next prime is 21475200793. The reversal of 21475200787 is 78700257412.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is an interprime number because it is at equal distance from previous prime (21475200781) and next prime (21475200793).

It is a 3-Lehmer number, since φ(21475200787) divides (21475200787-1)³.

It is a cyclic number.

It is not a de Polignac number, because 21475200787 - 2¹⁹ = 21474676499 is a prime.

It is a super-2 number, since 2×21475200787² (a number of 21 digits) contains 22 as substring.

It is a deceptive number, since it divides R_21475200786.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21475200781) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 29914 + ... + 209392.

It is an arithmetic number, because the mean of its divisors is an integer number (5368874980).

Almost surely, 2^21475200787 is an apocalyptic number.

21475200787 is the 119653-rd pentagonal number.

21475200787 is a deficient number, since it is larger than the sum of its proper divisors (299133).

21475200787 is a wasteful number, since it uses less digits than its factorization.

21475200787 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 299132.

The product of its (nonzero) digits is 219520, while the sum is 43.

The spelling of 21475200787 in words is "twenty-one billion, four hundred seventy-five million, two hundred thousand, seven hundred eighty-seven".