4002561551 has 4 divisors (see below), whose sum is σ = 4007497704. Its totient is φ = 3997625400.

The previous prime is 4002561547. The next prime is 4002561557. The reversal of 4002561551 is 1551652004.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 4002561551 - 2² = 4002561547 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 (4002561557) 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, 2466860 + ... + 2468481.

It is an arithmetic number, because the mean of its divisors is an integer number (1001874426).

Almost surely, 2^4002561551 is an apocalyptic number.

4002561551 is a deficient number, since it is larger than the sum of its proper divisors (4936153).

4002561551 is an equidigital number, since it uses as much as digits as its factorization.

4002561551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4936152.

The product of its (nonzero) digits is 6000, while the sum is 29.

The square root of 4002561551 is about 63265.8008010647. The cubic root of 4002561551 is about 1587.7398303913.

The spelling of 4002561551 in words is "four billion, two million, five hundred sixty-one thousand, five hundred fifty-one".