21025401487 has 2 divisors, whose sum is σ = 21025401488. Its totient is φ = 21025401486.

The previous prime is 21025401479. The next prime is 21025401541. The reversal of 21025401487 is 78410452012.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21025401487 - 2³ = 21025401479 is a prime.

It is a super-2 number, since 2×21025401487² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21025401407) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10512700743 + 10512700744.

It is an arithmetic number, because the mean of its divisors is an integer number (10512700744).

Almost surely, 2^21025401487 is an apocalyptic number.

21025401487 is a deficient number, since it is larger than the sum of its proper divisors (1).

21025401487 is an equidigital number, since it uses as much as digits as its factorization.

21025401487 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 17920, while the sum is 34.

Adding to 21025401487 its reverse (78410452012), we get a palindrome (99435853499).

The spelling of 21025401487 in words is "twenty-one billion, twenty-five million, four hundred one thousand, four hundred eighty-seven".